SHAMA SHAIK INFORMATION SYSTEM

Staying Safe on Social Network Sites

2008-12-13T16:57:00.003+03:00

The popularity of social networking sites continues to increase, especially among teenagers and young adults. The nature of these sites introduces security risks, so you should take certain precautions.

What are social networking sites?

Social networking sites, sometimes referred to as "friend-of-a-friend" sites, build upon the concept of traditional social networks where you are connected to new people through people you already know. The purpose of some networking sites may be purely social, allowing users to establish friendships or romantic relationships, while others may focus on establishing business connections.

Although the features of social networking sites differ, they all allow you to provide information about yourself and offer some type of communication mechanism (forums, chat rooms, email, instant messenger) that enables you to connect with other users. On some sites, you can browse for people based on certain criteria, while other sites require that you be "introduced" to new people through a connection you share. Many of the sites have communities or subgroups that may be based on a particular interest.

What security implications do these sites present?

Social networking sites rely on connections and communication, so they encourage you to provide a certain amount of personal information. When deciding how much information to reveal, people may not exercise the same amount of caution as they would when meeting someone in person because

the internet provides a sense of anonymity
the lack of physical interaction provides a false sense of security
they tailor the information for their friends to read, forgetting that others may see it
they want to offer insights to impress potential friends or associates

While the majority of people using these sites do not pose a threat, malicious people may be drawn to them because of the accessibility and amount of personal information available on them. The more information malicious people have about you, the easier it is for them to take advantage of you. Predators may form relationships online and then convince unsuspecting individuals to meet them in person. That could lead to a dangerous situation. The personal information can also be used to conduct a social engineering attack (see Avoiding Social Engineering and Phishing Attacks for more information). Using information that you provide about your location, hobbies, interests, and friends, a malicious person could impersonate a trusted friend or convince you that they have the authority to access other personal or financial data.

How can you protect yourself?

Limit the amount of personal information you post - Do not post information that would make you vulnerable (e.g., your address, information about your schedule or routine). If your connections post information about you, make sure the combined information is not more than you would be comfortable with strangers knowing.
Remember that the internet is a public resource - Only post information you are comfortable with anyone seeing. This includes information in your profile and in blogs and other forums. Also, once you post information online, you can't retract it. Even if you remove the information from a site, saved or cached versions may still exist on other people's machines (see Guidelines for Publishing Information Online for more information).
Be wary of strangers - The internet makes it easy for people to misrepresent their identities and motives (see Using Instant Messaging and Chat Rooms Safely for more information). Consider limiting the people who are allowed to contact you on these sites. If you interact with people you do not know, be cautious about the amount of information you reveal or agreeing to meet them in person.
Be skeptical - Don't believe everything you read online. People may post false or misleading information about various topics, including their own identities. This is not necessarily done with malicious intent; it could be unintentional, a product of exaggeration, or a joke. Take appropriate precautions, though, and try to verify the authenticity of any information before taken any action.
Check privacy policies - Some sites may share information such as email addresses or user preferences with other companies. This may lead to an increase in spam (see Reducing Spam for more information). Also, try to locate the policy for handling referrals to make sure that you do not unintentionally sign your friends up for spam. Some sites will continue to send email messages to anyone you refer until they join.

Children are especially susceptible to the threats that social networking sites present. Although many of these sites have age restrictions, children may misrepresent their ages so that they can join. By teaching children about internet safety, being aware of their online habits, and guiding them to appropriate sites, parents can make sure that the children become safe and responsible users (see Keeping Children Safe Online for more information).

Author: Mindi McDowell

Using Instant Messaging and Chat Rooms Safely

2008-12-13T16:57:00.001+03:00

Although they offer a convenient way to communicate with other people, there are dangers associated with tools that allow real-time communication.

What are the differences between some of the tools used for real-time communication?

Instant messaging (IM) - Commonly used for recreation, instant messaging is also becoming more widely used within corporations for communication between employees. IM, regardless of the specific software you choose, provides an interface for individuals to communicate one-on-one.
Chat rooms - Whether public or private, chat rooms are forums for particular groups of people to interact. Many chat rooms are based upon a shared characteristic; for example, there are chat rooms for people of particular age groups or interests. Although most IM clients support "chats" among multiple users, IM is traditionally one-to-one while chats are traditionally many-to-many.
Bots - A "chat robot," or "bot," is software that can interact with users through chat mechanisms, whether in IM or chat rooms. In some cases, users may be able to obtain current weather reports, stock status, or movie listings. In these instances, users are often aware that they are not interacting with an actual human. However, some users may be fooled by more sophisticated bots into thinking the responses they are receiving are from another person.

There are many software packages that incorporate one or more of these capabilities. A number of different technologies might be supported, including IM, Internet Relay Chat (IRC), or Jabber.

What are the dangers?

Identities can be elusive or ambiguous - Not only is it sometimes difficult to identify whether the "person" you are talking to is human, but human nature and behavior isn't predictable. People may lie about their identity, accounts may be compromised, users may forget to log out, or an account may be shared by multiple people. All of these things make it difficult to know who you're really talking to during a conversation.
Users are especially susceptible to certain types of attack - Trying to convince someone to run a program or click on a link is a common attack method, but it can be especially effective through IM and chat rooms. In a setting where a user feels comfortable with the "person" he or she is talking to, a malicious piece of software or an attacker has a better chance of convincing someone to fall into the trap (see Avoiding Social Engineering and Phishing Attacks for more information).
You don't know who else might be seeing the conversation - Online interactions are easily saved, and if you're using a free commercial service the exchanges may be archived on a server. You have no control over what happens to those logs. You also don't know if there's someone looking over the shoulder of the person you're talking to, or if an attacker might be "sniffing" your conversation.
The software you're using may contain vulnerabilities - Like any other software, chat software may have vulnerabilities that attackers can exploit.
Default security settings may be inappropriate - The default security settings in chat software tend to be relatively permissive to make it more open and "usable," and this can make you more susceptible to attacks.

How can you use these tools safely?

Evaluate your security settings - Check the default settings in your software and adjust them if they are too permissive. Make sure to disable automatic downloads. Some chat software offers the ability to limit interactions to only certain users, and you may want to take advantage of these restrictions.
Be conscious of what information you reveal - Be wary of revealing personal information unless you know who you are really talking to. You should also be careful about discussing anything you or your employer might consider sensitive business information over public IM or chat services (even if you are talking to someone you know in a one-to-one conversation).
Try to verify the identity of the person you are talking to, if it matters - In some forums and situations, the identity of the "person" you are talking to may not matter. However, if you need to have a degree of trust in that person, either because you are sharing certain types of information or being asked to take some action like following a link or running a program, make sure the "person" you are talking to is actually that person.
Don't believe everything you read - The information or advice you receive in a chat room or by IM may be false or, worse, malicious. Try to verify the information or instructions from outside sources before taking any action.
Keep software up to date - This includes the chat software, your browser, your operating system, your mail client, and, especially, your anti-virus software (see Understanding Patches and Understanding Anti-Virus Software for more information).

Authors: Mindi McDowell, Allen Householder

Understanding Digital Signatures

2008-12-13T16:56:00.001+03:00

Digital signatures are a way to verify that an email message is really from the person who supposedly sent it and that it hasn't been changed.

What is a digital signature?

You may have received emails that have a block of letters and numbers at the bottom of the message. Although it may look like useless text or some kind of error, this information is actually a digital signature. To generate a signature, a mathematical algorithm is used to combine the information in a key with the information in the message. The result is a random-looking string of letters and numbers.

Why would you use one?

Because it is so easy for attackers and viruses to "spoof" email addresses (see Using Caution with Email Attachments for more information), it is sometimes difficult to identify legitimate messages. Authenticity may be especially important for business correspondence—if you are relying on someone to provide or verify information, you want to be sure that the information is coming from the correct source. A signed message also indicates that changes have not been made to the content since it was sent; any changes would cause the signature to break.

How does it work?

Before you can understand how a digital signature works, there are some terms you should know:

Keys - Keys are used to create digital signatures. For every signature, there is a public key and a private key.
- Private key - The private key is the portion of the key you use to actually sign an email message. The private key is protected by a password, and you should never give your private key to anyone.
- Public key - The public key is the portion of the key that is available to other people. Whether you upload it to a public key ring or send it to someone, this is the key other people can use to check your signature. A list of other people who have signed your key is also included with your public key. You will only be able to see their identities if you already have their public keys on your key ring.
Key ring - A key ring contains public keys. You have a key ring that contains the keys of people who have sent you their keys or whose keys you have gotten from a public key server. A public key server contains keys of people who have chosen to upload their keys.
Fingerprint - When confirming a key, you will actually be confirming the unique series of letters and numbers that comprise the fingerprint of the key. The fingerprint is a different series of letters and numbers than the chunk of information that appears at the bottom of a signed email message.
Key certificates - When you select a key on a key ring, you will usually see the key certificate, which contains information about the key, such as the key owner, the date the key was created, and the date the key will expire.
"Web of trust" - When someone signs your key, they are confirming that the key actually belongs to you. The more signatures you collect, the stronger your key becomes. If someone sees that your key has been signed by other people that he or she trusts, he or she is more inclined to trust your key. Note: Just because someone else has trusted a key or you find it on a public key ring does not mean you should automatically trust it. You should always verify the fingerprint yourself.

The process for creating, obtaining, and using keys is fairly straightforward:

Generate a key using software such as PGP, which stands for Pretty Good Privacy, or GnuPG, which stands for GNU Privacy Guard.
Increase the authenticity of your key by having your key signed by co-workers or other associates who also have keys. In the process of signing your key, they will confirm that the fingerprint on the key you sent them belongs to you. By doing this, they verify your identity and indicate trust in your key.
Upload your signed key to a public key ring so that if someone gets a message with your signature, they can verify the digital signature.
Digitally sign your outgoing email messages. Most email clients have a feature to easily add your digital signature to your message.

Authors: Mindi McDowell, Allen Householder

Benefits of BCC

2008-12-13T16:55:00.003+03:00

Although in many situations it may be appropriate to list email recipients in the To: or CC: fields, sometimes using the BCC: field may be the most desirable option.

What is BCC?

BCC, which stands for blind carbon copy, allows you to hide recipients in email messages. Unlike addresses in the To: field or the CC: (carbon copy) field, addresses in the BCC: field cannot be seen by other users.

Why would you want to use BCC?

There are a few main reasons for using BCC:

Privacy - Sometimes it's beneficial, even necessary, for you to let recipients know who else is receiving your email message. However, there may be instances when you want to send the same message to multiple recipients without letting them know who else is receiving the message. If you are sending email on behalf of a business or organization, it may be especially important to keep lists of clients, members, or associates confidential. You may also want to avoid listing an internal email address on a message being sent to external recipients.
Another point to remember is that if you use the To: or CC: fields to list all of your recipients, these same recipients will also receive any replies to your message unless the sender removes them. If there is potential for a response that is not appropriate for all recipients, consider using BCC.
Tracking - Maybe you want to access or archive the email message you are sending at another email account. Or maybe you want to make someone, such as a supervisor or team member, aware of the email without actually involving them in the exchange. BCC allows you to accomplish these goals without advertising that you are doing it.
Respect for your recipients - Forwarded email messages frequently contain long lists of email addresses that were CC'd by previous senders. These addresses are highly likely to be active and valid, so they are very valuable to spammers. Furthermore, many email-borne viruses harvest email addresses contained in messages you've already received (not just the To: and From: fields, but from the body, too), so those long lists in forwarded messages pose a risk to all the accounts they point to if you get infected.
Many people frequently forward messages to their entire address books using CC. Encourage people who forward messages to you to use BCC so that your email address is less likely to appear in other people's inboxes and be susceptible to being harvested. To avoid becoming part of the problem, in addition to using BCC if you forward messages, take time to remove all existing email addresses within the message. The additional benefit is that the people you're sending the message to will appreciate not having to scroll through large sections of irrelevant information to get to the actual message.

How do you BCC an email message?

Most email clients have the option to BCC listed a few lines below the To: field. However, sometimes it is a separate option that is not listed by default. If you cannot locate it, check the help menu or the software's documentation.

If you want to BCC all recipients and your email client will not send a message without something in the To: field, consider using your own email address in that field. In addition to hiding the identity of other recipients, this option will enable you to confirm that the message was sent successfully.

Authors: Mindi McDowell, Allen Householder

Benefits and Risks of Free Email Services

2008-12-13T16:55:00.001+03:00

Although free email services are convenient for sending personal correspondence, you should not use them to send messages containing sensitive information.

What is the appeal of free email services?

Many service providers offer free email accounts (e.g., Yahoo!, Hotmail, Gmail). These email services typically provide you with a browser interface to access your mail. In addition to the monetary savings, these services often offer other benefits:

accessibility - Because you can access your account(s) from any computer, these services are useful if you cannot be near your computer or are in the process of relocating and do not have an ISP. Even if you are able to access your ISP-based email account remotely, being able to rely on a free email account is ideal if you are using a public computer or a shared wireless hot spot and are concerned about exposing the details of your primary account.
competitive features - With so many of these service providers competing for users, they now offer additional features such as large amounts of storage, spam filtering, virus protection, and enhanced fonts and graphics.
additional capabilities - It is becoming more common for service providers to package additional software or services (e.g., instant messaging) with their free email accounts to attract customers.

Free email accounts are also effective tools for reducing the amount of spam you receive at your primary email address. Instead of submitting your primary address when shopping online, requesting services, or participating in online forums, you can set up a free secondary address to use (see Reducing Spam for more information).

What risks are associated with free email services?

Although free email services have many benefits, you should not use them to send sensitive information. Because you are not paying for the account, the organization may not have a strong commitment to protecting you from various threats or to offering you the best service. Some of the elements you risk are

security - If your login, password, or messages are sent in plain text, they may easily be intercepted. If a service provider offers SSL encryption, you should use it. You can find out whether this is available by looking for a "secure mode" or by replacing the "http:" in the URL with "https:" (see Protecting Your Privacy for more information).
privacy - You aren't paying for your email account, but the service provider has to find some way to recover the costs of providing the service. One way of generating revenue is to sell advertising space, but another is to sell or trade information. Make sure to read the service provider's privacy policy or terms of use to see if your name, your email address, the email addresses in your address book, or any of the information in your profile has the potential of being given to other organizations (see Protecting Your Privacy for more information). If you are considering forwarding your work email to a free email account, check with your employer first. You do not want to violate any established security policies.
reliability - Although you may be able to access your account from any computer, you need to make sure that the account is going to be available when you want to access it. Familiarize yourself with the service provider's terms of service so that you know exactly what they have committed to providing you. For example, if the service ends or your account disappears, can you retrieve your messages? Does the service provider give you the ability to download messages that you want to archive onto your machine? Also, if you happen to be in a different time zone than the provider, you may find that their server maintenance interferes with your normal email routine.

Authors: Mindi McDowell, Allen Householder

Reducing Spam

2008-12-13T16:50:00.003+03:00

Spam is a common, and often frustrating, side effect to having an email account. Although you will probably not be able to eliminate it, there are ways to reduce it.

What is spam?

Spam is the electronic version of "junk mail." The term spam refers to unsolicited, often unwanted, email messages. Spam does not necessarily contain viruses—valid messages from legitimate sources could fall into this category.

How can you reduce the amount of spam?

There are some steps you can take to significantly reduce the amount of spam you receive:

Don't give your email address out arbitrarily - Email addresses have become so common that a space for them is often included on any form that asks for your address—even comment cards at restaurants. It seems harmless, so many people write them in the space provided without realizing what could happen to that information. For example, companies often enter the addresses into a database so that they can keep track of their customers and the customers' preferences. Sometimes these lists are sold to or shared with other companies, and suddenly you are receiving email that you didn't request.
Check privacy policies - Before submitting your email address online, look for a privacy policy. Most reputable sites will have a link to their privacy policy from any form where you're asked to submit personal data. You should read this policy before submitting your email address or any other personal information so that you know what the owners of the site plan to do with the information (see Protecting Your Privacy for more information).
Be aware of options selected by default - When you sign up for some online accounts or services, there may be a section that provides you with the option to receive email about other products and services. Sometimes there are options selected by default, so if you do not deselect them, you could begin to receive email from lists those lists as well.
Use filters - Many email programs offer filtering capabilities that allow you to block certain addresses or to only allow email from addresses on your contact list. Some ISPs offer spam "tagging" or filtering services, but legitimate messages misclassified as spam might be dropped before reaching your inbox. However, many ISPs that offer filtering services also provide options for tagging suspected spam messages so the end user can more easily identify them. This can be useful in conjunction with filtering capabilities provided by many email programs.
Don't follow links in spam messages - Some spam relies on generators that try variations of email addresses at certain domains. If you click a link within an email message or reply to a certain address, you are just confirming that your email address is valid. Unwanted messages that offer an "unsubscribe" option are particularly tempting, but this is often just a method for collecting valid addresses that are then sent other spam.
Disable the automatic downloading of graphics in HTML mail - Many spammers send HTML mail with a linked graphic file that is then used to track who opens the mail message—when your mail client downloads the graphic from their web server, they know you've opened the message. Disabling HTML mail entirely and viewing messages in plain text also prevents this problem.
Consider opening an additional email account - Many domains offer free email accounts. If you frequently submit your email address (for online shopping, signing up for services, or including it on something like a comment card), you may want to have a secondary email account to protect your primary email account from any spam that could be generated. You should also use a secondary account when posting to online bulletin boards, chat rooms, public mailing lists, or USENET so that you can get rid of when it starts filling up with spam.
Don't spam other people - Be a responsible and considerate user. Some people consider email forwards a type of spam, so be selective with the messages you redistribute. Don't forward every message to everyone in your address book, and if someone asks that you not forward messages to them, respect their request.

Authors: Mindi McDowell, Allen Householder

Using Caution with Email Attachments

2008-12-13T16:50:00.001+03:00

While email attachments are a popular and convenient way to send documents, they are also a common source of viruses. Use caution when opening attachments, even if they appear to have been sent by someone you know.

Why can email attachments be dangerous?

Some of the characteristics that make email attachments convenient and popular are also the ones that make them a common tool for attackers:

Email is easily circulated - Forwarding email is so simple that viruses can quickly infect many machines. Most viruses don't even require users to forward the email—they scan a users' computer for email addresses and automatically send the infected message to all of the addresses they find. Attackers take advantage of the reality that most users will automatically trust and open any message that comes from someone they know.
Email programs try to address all users' needs - Almost any type of file can be attached to an email message, so attackers have more freedom with the types of viruses they can send.
Email programs offer many "user-friendly" features - Some email programs have the option to automatically download email attachments, which immediately exposes your computer to any viruses within the attachments.

What steps can you take to protect yourself and others in your address book?

Be wary of unsolicited attachments, even from people you know - Just because an email message looks like it came from your mom, grandma, or boss doesn't mean that it did. Many viruses can "spoof" the return address, making it look like the message came from someone else. If you can, check with the person who supposedly sent the message to make sure it's legitimate before opening any attachments. This includes email messages that appear to be from your ISP or software vendor and claim to include patches or anti-virus software. ISPs and software vendors do not send patches or software in email.
Save and scan any attachments before opening them - If you have to open an attachment before you can verify the source, take the following steps:
1. Be sure the signatures in your anti-virus software are up to date (see Understanding Anti-Virus Software for more information)
2. Save the file to your computer or a disk
3. Manually scan the file using your anti-virus software
4. Open the file
Turn off the option to automatically download attachments - To simplify the process of reading email, many email programs offer the feature to automatically download attachments. Check your settings to see if your software offers the option, and make sure to disable it.
Consider additional security practices - You may be able to filter certain types of attachments through your email software (see Reducing Spam) or a firewall (see Understanding Firewalls).

Both the National Cyber Security Alliance and US-CERT have identified this topic as one of the top tips for home users.

Authors: Mindi McDowell, Allen Householder

Avoiding the Pitfalls of Online Trading

2008-12-06T17:51:00.001+03:00

Online trading can be an easy, cost-effective way to manage investments. However, online investors are often targets of scams, so take precautions to ensure that you do not become a victim.

What is online trading?

Online trading allows you to conduct investment transactions over the internet. The accessibility of the internet makes it possible for you to research and invest in opportunities from any location at any time. It also reduces the amount of resources (time, effort, and money) you have to devote to managing these accounts and transactions.

What are the risks?

Recognizing the importance of safeguarding your money, legitimate brokerages take steps to ensure that their transactions are secure. However, online brokerages and the investors who use them are appealing targets for attackers. The amount of financial information in a brokerage's database makes it valuable; this information can be traded or sold for personal profit. Also, because money is regularly transferred through these accounts, malicious activity may not be noticed immediately. To gain access to these databases, attackers may use Trojan horses or other types of malicious code (see Why is Cyber Security a Problem? for more information).

Attackers may also attempt to collect financial information by targeting the current or potential investors directly. These attempts may take the form of social engineering or phishing attacks (see Avoiding Social Engineering and Phishing Attacks for more information). With methods that include setting up fraudulent investment opportunities or redirecting users to malicious sites that appear to be legitimate, attackers try to convince you to provide them with financial information that they can then use or sell. If you have been victimized, both your money and your identity may be at risk (see Preventing and Responding to Identity Theft for more information).

How can you protect yourself?

Research your investment opportunities - Take advantage of resources such as the U.S. Securities and Exchange Commission's EDGAR database and your state's securities commission (found through the North American Securities Administrators Association) to investigate companies.
Be wary of online information - Anyone can publish information on the internet, so try to verify any online research through other methods before investing any money. Also be cautious of "hot" investment opportunities advertised online or in email.
Check privacy policies - Before providing personal or financial information, check the web site's privacy policy. Make sure you understand how your information will be stored and used (see Protecting Your Privacy for more information).
Make sure that your transactions are encrypted - When information is sent over the internet, attackers may be able to intercept it. Encryption prevents the attackers from being able to view the information.
Verify that the web site is legitimate - Attackers may redirect you to a malicious web site that looks identical to a legitimate one. They then convince you to submit your personal and financial information, which they use for their own gain. Check the web site's certificate to make sure it is legitimate (see Understanding Web Site Certificates for more information).
Monitor your investments - Regularly check your accounts for any unusual activity. Report unauthorized transactions immediately.
Use and maintain anti-virus software - Anti-virus software recognizes and protects your computer against most known viruses. However, because attackers are continually writing new viruses, it is important to keep your virus definitions current (see Understanding Anti-Virus Software for more information).
Use anti-spyware tools - Spyware is a common source of viruses, and attackers may use it to access information on your computer. You can minimize the number of infections by using a legitimate program that identifies and removes spyware (see Recognizing and Avoiding Spyware for more information).
Keep software up to date - Install software patches so that attackers can't take advantage of known problems or vulnerabilities (see Understanding Patches for more information). Enable automatic updates if the option is available.
Evaluate your security settings - By adjusting the security settings in your browser, you may limit your risk of certain attacks (see Evaluating Your Web Browser's Security Settings for more information).

The following sites offer additional information and guidance:

U.S. Securities and Exchange Commission - http://www.sec.gov/investor/pubs/cyberfraud.htm
National Consumers League - http://www.fraud.org/tips/internet/investment.htm

Author: Mindi McDowell

Identifying Hoaxes and Urban Legends

2008-12-06T17:50:00.002+03:00

Chain letters are familiar to anyone with an email account, whether they are sent by strangers or well-intentioned friends or family members. Try to verify the information before following any instructions or passing the message along.

Why are chain letters a problem?

The most serious problem is from chain letters that mask viruses or other malicious activity. But even the ones that seem harmless may have negative repercussions if you forward them:

they consume bandwidth or space within the recipient's inbox
you force people you know to waste time sifting through the messages and possibly taking time to verify the information
you are spreading hype and, often, unnecessary fear and paranoia

What are some types of chain letters?

There are two main types of chain letters:

Hoaxes - Hoaxes attempt to trick or defraud users. A hoax could be malicious, instructing users to delete a file necessary to the operating system by claiming it is a virus. It could also be a scam that convinces users to send money or personal information. Phishing attacks could fall into this category (see Avoiding Social Engineering and Phishing Attacks for more information).
Urban legends - Urban legends are designed to be redistributed and usually warn users of a threat or claim to be notifying them of important or urgent information. Another common form are the emails that promise users monetary rewards for forwarding the message or suggest that they are signing something that will be submitted to a particular group. Urban legends usually have no negative effect aside from wasted bandwidth and time.

How can you tell if the email is a hoax or urban legend?

Some messages are more suspicious than others, but be especially cautious if the message has any of the characteristics listed below. These characteristics are just guidelines—not every hoax or urban legend has these attributes, and some legitimate messages may have some of these characteristics:

it suggests tragic consequences for not performing some action
it promises money or gift certificates for performing some action
it offers instructions or attachments claiming to protect you from a virus that is undetected by anti-virus software
it claims it's not a hoax
there are multiple spelling or grammatical errors, or the logic is contradictory
there is a statement urging you to forward the message
it has already been forwarded multiple times (evident from the trail of email headers in the body of the message)

If you want to check the validity of an email, there are some web sites that provide information about hoaxes and urban legends:

Urban Legends and Folklore - http://urbanlegends.about.com/
Urban Legends Reference Pages - http://www.snopes.com/
Hoaxbusters - http://hoaxbusters.ciac.org/
TruthOrFiction.com - http://www.truthorfiction.com/
Symantec Security Response Hoaxes - http://www.symantec.com/avcenter/hoax.html
McAfee Security Virus Hoaxes - http://vil.mcafee.com/hoax.asp

Authors: Mindi McDowell, Allen Householder

Understanding Denial-of-Service Attacks

2008-12-06T17:50:00.001+03:00

You may have heard of denial-of-service attacks launched against web sites, but you can also be a victim of these attacks. Denial-of-service attacks can be difficult to distinguish from common network activity, but there are some indications that an attack is in progress.

What is a denial-of-service (DoS) attack?

In a denial-of-service (DoS) attack, an attacker attempts to prevent legitimate users from accessing information or services. By targeting your computer and its network connection, or the computers and network of the sites you are trying to use, an attacker may be able to prevent you from accessing email, web sites, online accounts (banking, etc.), or other services that rely on the affected computer.

The most common and obvious type of DoS attack occurs when an attacker "floods" a network with information. When you type a URL for a particular web site into your browser, you are sending a request to that site's computer server to view the page. The server can only process a certain number of requests at once, so if an attacker overloads the server with requests, it can't process your request. This is a "denial of service" because you can't access that site.

An attacker can use spam email messages to launch a similar attack on your email account. Whether you have an email account supplied by your employer or one available through a free service such as Yahoo or Hotmail, you are assigned a specific quota, which limits the amount of data you can have in your account at any given time. By sending many, or large, email messages to the account, an attacker can consume your quota, preventing you from receiving legitimate messages.

What is a distributed denial-of-service (DDoS) attack?

In a distributed denial-of-service (DDoS) attack, an attacker may use your computer to attack another computer. By taking advantage of security vulnerabilities or weaknesses, an attacker could take control of your computer. He or she could then force your computer to send huge amounts of data to a web site or send spam to particular email addresses. The attack is "distributed" because the attacker is using multiple computers, including yours, to launch the denial-of-service attack.

How do you avoid being part of the problem?

Unfortunately, there are no effective ways to prevent being the victim of a DoS or DDoS attack, but there are steps you can take to reduce the likelihood that an attacker will use your computer to attack other computers:

Install and maintain anti-virus software (see Understanding Anti-Virus Software for more information).
Install a firewall, and configure it to restrict traffic coming into and leaving your computer (see Understanding Firewalls for more information).
Follow good security practices for distributing your email address (see Reducing Spam for more information). Applying email filters may help you manage unwanted traffic.

How do you know if an attack is happening?

Not all disruptions to service are the result of a denial-of-service attack. There may be technical problems with a particular network, or system administrators may be performing maintenance. However, the following symptoms could indicate a DoS or DDoS attack:

unusually slow network performance (opening files or accessing web sites)
unavailability of a particular web site
inability to access any web site
dramatic increase in the amount of spam you receive in your account

What do you do if you think you are experiencing an attack?

Even if you do correctly identify a DoS or DDoS attack, it is unlikely that you will be able to determine the actual target or source of the attack. Contact the appropriate technical professionals for assistance.

If you notice that you cannot access your own files or reach any external web sites from your work computer, contact your network administrators. This may indicate that your computer or your organization's network is being attacked.
If you are having a similar experience on your home computer, consider contacting your Internet service provider (ISP). If there is a problem, the ISP might be able to advise you of an appropriate course of action.

Author: Mindi McDowell

Avoiding Social Engineering and Phishing Attacks

2008-12-06T17:49:00.000+03:00

Do not give sensitive information to anyone unless you are sure that they are indeed who they claim to be and that they should have access to the information.

What is a social engineering attack?

To launch a social engineering attack, an attacker uses human interaction (social skills) to obtain or compromise information about an organization or its computer systems. An attacker may seem unassuming and respectable, possibly claiming to be a new employee, repair person, or researcher and even offering credentials to support that identity. However, by asking questions, he or she may be able to piece together enough information to infiltrate an organization's network. If an attacker is not able to gather enough information from one source, he or she may contact another source within the same organization and rely on the information from the first source to add to his or her credibility.

What is a phishing attack?

Phishing is a form of social engineering. Phishing attacks use email or malicious web sites to solicit personal, often financial, information. Attackers may send email seemingly from a reputable credit card company or financial institution that requests account information, often suggesting that there is a problem. When users respond with the requested information, attackers can use it to gain access to the accounts.

How do you avoid being a victim?

Be suspicious of unsolicited phone calls, visits, or email messages from individuals asking about employees or other internal information. If an unknown individual claims to be from a legitimate organization, try to verify his or her identity directly with the company.
Do not provide personal information or information about your organization, including its structure or networks, unless you are certain of a person's authority to have the information.
Do not reveal personal or financial information in email, and do not respond to email solicitations for this information. This includes following links sent in email.
Don't send sensitive information over the Internet before checking a web site's security (see Protecting Your Privacy for more information).
Pay attention to the URL of a web site. Malicious web sites may look identical to a legitimate site, but the URL may use a variation in spelling or a different domain (e.g., .com vs. .net).
If you are unsure whether an email request is legitimate, try to verify it by contacting the company directly. Do not use contact information provided on a web site connected to the request; instead, check previous statements for contact information. Information about known phishing attacks is also available online from groups such as the Anti-Phishing Working Group (http://www.antiphishing.org/phishing_archive.html).
Install and maintain anti-virus software, firewalls, and email filters to reduce some of this traffic (see Understanding Firewalls, Understanding Anti-Virus Software, and Reducing Spam for more information).

What do you do if you think you are a victim?

If you believe you might have revealed sensitive information about your organization, report it to the appropriate people within the organization, including network administrators. They can be alert for any suspicious or unusual activity.
If you believe your financial accounts may be compromised, contact your financial institution immediately and close any accounts that may have been compromised. Watch for any unexplainable charges to your account.
Consider reporting the attack to the police, and file a report with the Federal Trade Commission (http://www.ftc.gov/).

Author: Mindi McDowell

Recognizing and Avoiding Spyware

2008-12-06T17:48:00.002+03:00

Because of its popularity, the internet has become an ideal target for advertising. As a result, spyware, or adware, has become increasingly prevalent. When troubleshooting problems with your computer, you may discover that the source of the problem is spyware software that has been installed on your machine without your knowledge.

What is spyware?

Despite its name, the term "spyware" doesn't refer to something used by undercover operatives, but rather by the advertising industry. In fact, spyware is also known as "adware." It refers to a category of software that, when installed on your computer, may send you pop-up ads, redirect your browser to certain web sites, or monitor the web sites that you visit. Some extreme, invasive versions of spyware may track exactly what keys you type. Attackers may also use spyware for malicious purposes.

Because of the extra processing, spyware may cause your computer to become slow or sluggish. There are also privacy implications:

What information is being gathered?
Who is receiving it?
How is it being used?

How do you know if there is spyware on your computer?

The following symptoms may indicate that spyware is installed on your computer:

you are subjected to endless pop-up windows
you are redirected to web sites other than the one you typed into your browser
new, unexpected toolbars appear in your web browser
new, unexpected icons appear in the task tray at the bottom of your screen
your browser's home page suddenly changed
the search engine your browser opens when you click "search" has been changed
certain keys fail to work in your browser (e.g., the tab key doesn't work when you are moving to the next field within a form)
random Windows error messages begin to appear
your computer suddenly seems very slow when opening programs or processing tasks (saving files, etc.)

How can you prevent spyware from installing on your computer?

To avoid unintentionally installing it yourself, follow these good security practices:

Don't click on links within pop-up windows - Because pop-up windows are often a product of spyware, clicking on the window may install spyware software on your computer. To close the pop-up window, click on the "X" icon in the titlebar instead of a "close" link within the window.
Choose "no" when asked unexpected questions - Be wary of unexpected dialog boxes asking whether you want to run a particular program or perform another type of task. Always select "no" or "cancel," or close the dialog box by clicking the "X" icon in the titlebar.
Be wary of free downloadable software - There are many sites that offer customized toolbars or other features that appeal to users. Don't download programs from sites you don't trust, and realize that you may be exposing your computer to spyware by downloading some of these programs.
Don't follow email links claiming to offer anti-spyware software - Like email viruses, the links may serve the opposite purpose and actually install the spyware it claims to be eliminating.

As an additional good security practice, especially if you are concerned that you might have spyware on your machine and want to minimize the impact, consider taking the following action:

Adjust your browser preferences to limit pop-up windows and cookies - Pop-up windows are often generated by some kind of scripting or active content. Adjusting the settings within your browser to reduce or prevent scripting or active content may reduce the number of pop-up windows that appear. Some browsers offer a specific option to block or limit pop-up windows. Certain types of cookies are sometimes considered spyware because they reveal what web pages you have visited. You can adjust your privacy settings to only allow cookies for the web site you are visiting (see Browsing Safely: Understanding Active Content and Cookies and Evaluating Your Web Browser's Security Settings for more information).

How do you remove spyware?

Run a full scan on your computer with your anti-virus software - Some anti-virus software will find and remove spyware, but it may not find the spyware when it is monitoring your computer in real time. Set your anti-virus software to prompt you to run a full scan periodically (see Understanding Anti-Virus Software for more information).
Run a legitimate product specifically designed to remove spyware - Many vendors offer products that will scan your computer for spyware and remove any spyware software. Popular products include Lavasoft's Ad-Aware, Webroot's SpySweeper, PestPatrol, and Spybot Search and Destroy.
Make sure that your anti-virus and anti-spyware software are compatible - Take a phased approach to installing the software to ensure that you don't unintentionally introduce problems (see Coordinating Virus and Spyware Defense for more information).

Authors: Mindi McDowell, Matt Lytle

Recovering from Viruses, Worms, and Trojan Horses

2008-12-06T17:48:00.001+03:00

Unfortunately, many users are victims of viruses, worms, or Trojan horses. If your computer gets infected with malicious code, there are steps you can take to recover.

How do you know your computer is infected?

Unfortunately, there is no particular way to identify that your computer has been infected with malicious code. Some infections may completely destroy files and shut down your computer, while others may only subtly affect your computer's normal operations. Be aware of any unusual or unexpected behaviors. If you are running anti-virus software, it may alert you that it has found malicious code on your computer. The anti-virus software may be able to clean the malicious code automatically, but if it can't, you will need to take additional steps.

What can you do if you are infected?

Minimize the damage - If you are at work and have access to an IT department, contact them immediately. The sooner they can investigate and clean your computer, the less damage to your computer and other computers on the network. If you are on your home computer or a laptop, disconnect your computer from the internet. By removing the internet connection, you prevent an attacker or virus from being able to access your computer and perform tasks such as locating personal data, manipulating or deleting files, or using your computer to attack other computers.
Remove the malicious code - If you have anti-virus software installed on your computer, update the virus definitions (if possible), and perform a manual scan of your entire system. If you do not have anti-virus software, you can purchase it at a local computer store (see Understanding Anti-Virus Software for more information). If the software can't locate and remove the infection, you may need to reinstall your operating system, usually with a system restore disk that is often supplied with a new computer. Note that reinstalling or restoring the operating system typically erases all of your files and any additional software that you have installed on your computer. After reinstalling the operating system and any other software, install all of the appropriate patches to fix known vulnerabilities (see Understanding Patches for more information).

How can you reduce the risk of another infection?

Dealing with the presence of malicious code on your computer can be a frustrating experience that can cost you time, money, and data. The following recommendations will build your defense against future infections:

use and maintain anti-virus software - Anti-virus software recognizes and protects your computer against most known viruses. However, attackers are continually writing new viruses, so it is important to keep your anti-virus software current (see Understanding Anti-Virus Software for more information).
change your passwords - Your original passwords may have been compromised during the infection, so you should change them. This includes passwords for web sites that may have been cached in your browser. Make the passwords difficult for attackers to guess (see Choosing and Protecting Passwords for more information).
keep software up to date - Install software patches so that attackers can't take advantage of known problems or vulnerabilities (see Understanding Patches for more information). Many operating systems offer automatic updates. If this option is available, you should enable it.
install or enable a firewall - Firewalls may be able to prevent some types of infection by blocking malicious traffic before it can enter your computer (see Understanding Firewalls for more information). Some operating systems actually include a firewall, but you need to make sure it is enabled.
use anti-spyware tools - Spyware is a common source of viruses, but you can minimize the number of infections by using a legitimate program that identifies and removes spyware (see Recognizing and Avoiding Spyware for more information).
follow good security practices - Take appropriate precautions when using email and web browsers so that you reduce the risk that your actions will trigger an infection (see other US-CERT security tips for more information).

As a precaution, maintain backups of your files on CDs or DVDs so that you have saved copies if you do get infected again.

Additional information

Author: Mindi McDowell

Preventing and Responding to Identity Theft

2008-12-06T17:47:00.004+03:00

Identity theft, or identity fraud, is a crime that can have substantial financial and emotional consequences. Take precautions with personal information; and if you become a victim, act immediately to minimize the damage.

Is identity theft just a problem for people who submit information online?

You can be a victim of identity theft even if you never use a computer. Malicious people may be able to obtain personal information (such as credit card numbers, phone numbers, account numbers, and addresses) by stealing your wallet, overhearing a phone conversation, rummaging through your trash (a practice known as dumpster diving), or picking up a receipt at a restaurant that has your account number on it. If a thief has enough information, he or she may be able to impersonate you to purchase items, open new accounts, or apply for loans.

The internet has made it easier for thieves to obtain personal and financial data. Most companies and other institutions store information about their clients in databases; if a thief can access that database, he or she can obtain information about many people at once rather than focus on one person at a time. The internet has also made it easier for thieves to sell or trade the information, making it more difficult for law enforcement to identify and apprehend the criminals.

How are victims of online identity theft chosen?

Identity theft is usually a crime of opportunity, so you may be victimized simply because your information is available. Thieves may target customers of certain companies for a variety of reasons; for example, a company database is easily accessible, the demographics of the customers are appealing, or there is a market for specific information. If your information is stored in a database that is compromised, you may become a victim of identity theft.

Are there ways to avoid being a victim?

Unfortunately, there is no way to guarantee that you will not be a victim of online identity theft. However, there are ways to minimize your risk:

Do business with reputable companies - Before providing any personal or financial information, make sure that you are interacting with a reputable, established company. Some attackers may try to trick you by creating malicious web sites that appear to be legitimate, so you should verify the legitimacy before supplying any information (see Avoiding Social Engineering and Phishing Attacks and Understanding Web Site Certificates for more information).
Take advantage of security features - Passwords and other security features add layers of protection if used appropriately (see Choosing and Protecting Passwords and Supplementing Passwords for more information).
Check privacy policies - Take precautions when providing information, and make sure to check published privacy policies to see how a company will use or distribute your information (see Protecting Your Privacy and How Anonymous Are You? for more information). Many companies allow customers to request that their information not be shared with other companies; you should be able to locate the details in your account literature or by contacting the company directly.
Be careful what information you publicize - Attackers may be able to piece together information from a variety of sources. Avoid posting personal data in public forums (see Guidelines for Publishing Information Online for more information).
Use and maintain anti-virus software and a firewall - Protect yourself against viruses and Trojan horses that may steal or modify the data on your own computer and leave you vulnerable by using anti-virus software and a firewall (see Understanding Anti-Virus Software and Understanding Firewalls for more information). Make sure to keep your virus definitions up to date.
Be aware of your account activity - Pay attention to your statements, and check your credit report yearly. You are entitled to a free copy of your credit report from each of the main credit reporting companies once every twelve months (see AnnualCreditReport.com for more information).

How do you know if your identity has been stolen?

Companies have different policies for notifying customers when they discover that someone has accessed a customer database. However, you should be aware of changes in your normal account activity. The following are examples of changes that could indicate that someone has accessed your information:

unusual or unexplainable charges on your bills
phone calls or bills for accounts, products, or services that you do not have
failure to receive regular bills or mail
new, strange accounts appearing on your credit report
unexpected denial of your credit card

What can you do if you think, or know, that your identity has been stolen?

Recovering from identity theft can be a long, stressful, and potentially costly process. Many credit card companies have adopted policies that try to minimize the amount of money you are liable for, but the implications can extend beyond your existing accounts. To minimize the extent of the damage, take action as soon as possible:

Contact companies, including banks, where you have accounts - Inform the companies where you have accounts that someone may be using your identity, and find out if there have been any unauthorized transactions. Close accounts so that future charges are denied. In addition to calling the company, send a letter so there is a record of the problem.
Contact the main credit reporting companies (Equifax, Experian, TransUnion) - Check your credit report to see if there has been unexpected or unauthorized activity. Have a fraud alerts placed on your credit reports to prevent new accounts being opened without verification.
File a report - File a report with the local police so there is an official record of the incident. You can also file a complaint with the Federal Trade Commission.
Consider other information that may be at risk - Depending what information was stolen, you may need to contact other agencies; for example, if a thief has access to your Social Security number, contact the Social Security Administration. You should also contact the Department of Motor Vehicles if your driver's license or car registration have been stolen.

The following sites offer additional information and guidance for recovering from identity theft:

Federal Trade Commission - http://www.ftc.gov/bcp/edu/microsites/idtheft/
United States Department of Justice - http://www.usdoj.gov/criminal/fraud/websites/idtheft.html
Social Security Administration - http://www.ssa.gov/pubs/idtheft.htm

Author: Mindi McDowell

Understanding Hidden Threats: Rootkits and Botnets

2008-12-06T17:47:00.001+03:00

Attackers are continually finding new ways to access computer systems. The use of hidden methods such as rootkits and botnets has increased, and you may be a victim without even realizing it.

What are rootkits and botnets?

A rootkit is a piece of software that can be installed and hidden on your computer without your knowledge. It may be included in a larger software package or installed by an attacker who has been able to take advantage of a vulnerability on your computer or has convinced you to download it (see Avoiding Social Engineering and Phishing Attacks for more information). Rootkits are not necessarily malicious, but they may hide malicious activities. Attackers may be able to access information, monitor your actions, modify programs, or perform other functions on your computer without being detected.

Botnet is a term derived from the idea of bot networks. In its most basic form, a bot is simply an automated computer program, or robot. In the context of botnets, bots refer to computers that are able to be controlled by one, or many, outside sources. An attacker usually gains control by infecting the computers with a virus or other malicious code that gives the attacker access. Your computer may be part of a botnet even though it appears to be operating normally. Botnets are often used to conduct a range of activities, from distributing spam and viruses to conducting denial-of-service attacks (see Understanding Denial-of-Service Attacks for more information).

Why are they considered threats?

The main problem with both rootkits and botnets is that they are hidden. Although botnets are not hidden the same way rootkits are, they may be undetected unless you are specifically looking for certain activity. If a rootkit has been installed, you may not be aware that your computer has been compromised, and traditional anti-virus software may not be able to detect the malicious programs. Attackers are also creating more sophisticated programs that update themselves so that they are even harder to detect.

Attackers can use rootkits and botnets to access and modify personal information, attack other computers, and commit other crimes, all while remaining undetected. By using multiple computers, attackers increase the range and impact of their crimes. Because each computer in a botnet can be programmed to execute the same command, an attacker can have each of them scanning multiple computers for vulnerabilities, monitoring online activity, or collecting the information entered in online forms.

What can you do to protect yourself?

If you practice good security habits, you may reduce the risk that your computer will be compromised:

Use and maintain anti-virus software - Anti-virus software recognizes and protects your computer against most known viruses, so you may be able to detect and remove the virus before it can do any damage (see Understanding Anti-Virus Software for more information). Because attackers are continually writing new viruses, it is important to keep your definitions up to date. Some anti-virus vendors also offer anti-rootkit software.
Install a firewall - Firewalls may be able to prevent some types of infection by blocking malicious traffic before it can enter your computer and limiting the traffic you send (see Understanding Firewalls for more information). Some operating systems actually include a firewall, but you need to make sure it is enabled.
Use good passwords - Select passwords that will be difficult for attackers to guess, and use different passwords for different programs and devices (see Choosing and Protecting Passwords for more information). Do not choose options that allow your computer to remember your passwords.
Keep software up to date - Install software patches so that attackers can't take advantage of known problems or vulnerabilities (see Understanding Patches for more information). Many operating systems offer automatic updates. If this option is available, you should enable it.
Follow good security practices - Take appropriate precautions when using email and web browsers to reduce the risk that your actions will trigger an infection (see other US-CERT security tips for more information).

Unfortunately, if there is a rootkit on your computer or an attacker is using your computer in a botnet, you may not know it. Even if you do discover that you are a victim, it is difficult for the average user to effectively recover. The attacker may have modified files on your computer, so simply removing the malicious files may not solve the problem, and you may not be able to safely trust a prior version of a file. If you believe that you are a victim, consider contacting a trained system administrator.

As an alternative, some vendors are developing products and tools that may remove a rootkit from your computer. If the software cannot locate and remove the infection, you may need to reinstall your operating system, usually with a system restore disk that is often supplied with a new computer. Note that reinstalling or restoring the operating system typically erases all of your files and any additional software that you have installed on your computer. Also, the infection may be located at such a deep level that it cannot be removed by simply reinstalling or restoring the operating system.

Author: Mindi McDowell

Understanding Hidden Threats: Corrupted Software Files

2008-12-06T17:46:00.001+03:00

Malicious code is not always hidden in web page scripts or unusual file formats. Attackers may corrupt types of files that you would recognize and typically consider safe, so you should take precautions when opening files from other people.

What types of files can attackers corrupt?

An attacker may be able to insert malicious code into any file, including common file types that you would normally consider safe. These files may include documents created with word processing software, spreadsheets, or image files. After corrupting the file, an attacker may distribute it through email or post it to a web site. Depending on the type of malicious code, you may infect your computer by just opening the file.

When corrupting files, attackers often take advantage of vulnerabilities that they discover in the software. These vulnerabilities may allow attackers to insert and execute malicious scripts or code, sometimes without being detected. Sometimes the vulnerability involves a combination of certain files (such as a particular piece of software running on a particular operating system) or only affects certain versions of a software program.

What problems can malicious files cause?

There are various types of malicious code, including viruses, worms, and Trojan horses (see Why is Cyber Security a Problem? for more information). However, the range of consequences varies even within these categories. The malicious code may be designed to perform one or more functions, including

interfering with your computer's ability to process information by consuming memory or bandwidth (causing your computer to become significantly slower or even "freeze")
installing, altering, or deleting files on your computer
giving the attacker access to your computer
using your computer to attack other computers (see Understanding Denial-of-Service Attacks for more information)

How can you protect yourself?

Use and maintain anti-virus software - Anti-virus software recognizes and protects your computer against most known viruses, so you may be able to detect and remove the virus before it can do any damage (see Understanding Anti-Virus Software for more information). Because attackers are continually writing new viruses, it is important to keep your definitions up to date.
Use caution with email attachments - Do not open email attachments that you were not expecting, especially if they are from people you do not know. If you decide to open an email attachment, scan it for viruses first (see Using Caution with Email Attachments for more information). Not only is it possible for attackers to "spoof" the source of an email message, your legitimate contacts may unknowingly send you an infected file.
Be wary of downloadable files on web sites - Avoid downloading files from sites that you do not trust. If you are getting the files from a supposedly secure site, look for a web site certificate (see Understanding Web Site Certificates for more information). If you do download a file from a web site, consider saving it to your desktop and manually scanning it for viruses before opening it.
Keep software up to date - Install software patches so that attackers cannot take advantage of known problems or vulnerabilities (see Understanding Patches for more information). Many operating systems offer automatic updates. If this option is available, you should enable it.
Take advantage of security settings - Check the security settings of your email client and your web browser (see Evaluating Your Web Browser's Security Settings for more information). Apply the highest level of security available that still gives you the functionality you need. In email clients, turn off the option to automatically download attachments.

Related information

Author: Mindi McDowell

Keeping Children Safe Online

2008-12-06T17:45:00.001+03:00

Children present unique security risks when they use a computer—not only do you have to keep them safe, you have to protect the data on your computer. By taking some simple steps, you can dramatically reduce the threats.

What unique risks are associated with children?

When a child is using your computer, normal safeguards and security practices may not be sufficient. Children present additional challenges because of their natural characteristics: innocence, curiosity, desire for independence, and fear of punishment. You need to consider these characteristics when determining how to protect your data and the child.

You may think that because the child is only playing a game, or researching a term paper, or typing a homework assignment, he or she can't cause any harm. But what if, when saving her paper, the child deletes a necessary program file? Or what if she unintentionally visits a malicious web page that infects your computer with a virus? These are just two possible scenarios. Mistakes happen, but the child may not realize what she's done or may not tell you what happened because she's afraid of getting punished.

Online predators present another significant threat, particularly to children. Because the nature of the internet is so anonymous, it is easy for people to misrepresent themselves and manipulate or trick other users (see Avoiding Social Engineering and Phishing Attacks for some examples). Adults often fall victim to these ploys, and children, who are usually much more open and trusting, are even easier targets. The threat is even greater if a child has access to email or instant messaging programs, visits chat rooms, and/or uses social networking sites (see Using Instant Messaging and Chat Rooms Safely and Staying Safe on Social Network Sites for more information).

What can you do?

Be involved - Consider activities you can work on together, whether it be playing a game, researching a topic you had been talking about (e.g., family vacation spots, a particular hobby, a historical figure), or putting together a family newsletter. This will allow you to supervise your child's online activities while teaching her good computer habits.
Keep your computer in an open area - If your computer is in a high-traffic area, you will be able to easily monitor the computer activity. Not only does this accessibility deter a child from doing something she knows she's not allowed to do, it also gives you the opportunity to intervene if you notice a behavior that could have negative consequences.
Set rules and warn about dangers - Make sure your child knows the boundaries of what she is allowed to do on the computer. These boundaries should be appropriate for the child's age, knowledge, and maturity, but they may include rules about how long she is allowed to be on the computer, what sites she is allowed to visit, what software programs she can use, and what tasks or activities she is allowed to do. You should also talk to children about the dangers of the internet so that they recognize suspicious behavior or activity. The goal isn't to scare them, it's to make them more aware.
Monitor computer activity - Be aware of what your child is doing on the computer, including which web sites she is visiting. If she is using email, instant messaging, or chat rooms, try to get a sense of who she is corresponding with and whether she actually knows them.
Keep lines of communication open - Let your child know that she can approach you with any questions or concerns about behaviors or problems she may have encountered on the computer.
Consider partitioning your computer into separate accounts - Most operating systems (including Windows XP, Mac OS X, and Linux) give you the option of creating a different user account for each user. If you're worried that your child may accidentally access, modify, and/or delete your files, you can give her a separate account and decrease the amount of access and number of privileges she has.
If you don't have separate accounts, you need to be especially careful about your security settings. In addition to limiting functionality within your browser (see Evaluating Your Web Browser's Security Settings for more information), avoid letting your browser remember passwords and other personal information (see Browsing Safely: Understanding Active Content and Cookies). Also, it is always important to keep your virus definitions up to date (see Understanding Anti-Virus Software).
Consider implementing parental controls - You may be able to set some parental controls within your browser. For example, Internet Explorer allows you to restrict or allow certain web sites to be viewed on your computer, and you can protect these settings with a password. To find those options, click Tools on your menu bar, select Internet Options..., choose the Content tab, and click the Enable... button under Content Advisor.
There are other resources you can use to control and/or monitor your child's online activity. Some ISPs offer services designed to protect children online. Contact your ISP to see if any of these services are available. There are also special software programs you can install on your computer. Different programs offer different features and capabilities, so you can find one that best suits your needs. The following web sites offer lists of software, as well as other useful information about protecting children online:
- GetNetWise - http://kids.getnetwise.org/ - Click Tools for Families to reach a page that allows you to search for software based on characteristics like what the tool does and what operating system you have on your computer.
- Yahooligans! Parents' Guide - http://yahooligans.yahoo.com/parents/ - Click Blocking and Filtering under Related Websites on the left sidebar to reach a list of software.

Authors: Mindi McDowell, Allen Householder

Real-World Warnings Keep You Safe Online

2008-12-06T17:44:00.000+03:00

Many of the warning phrases you probably heard from your parents and teachers are also applicable to using computers and the internet.

Why are these warnings important?

Like the real world, technology and the internet present dangers as well as benefits. Equipment fails, attackers may target you, and mistakes and poor judgment happen. Just as you take precautions to protect yourself in the real world, you need to take precautions to protect yourself online. For many users, computers and the internet are unfamiliar and intimidating, so it is appropriate to approach them the same way we urge children to approach the real world.

What are some warnings to remember?

Don't trust candy from strangers - Finding something on the internet does not guarantee that it is true. Anyone can publish information online, so before accepting a statement as fact or taking action, verify that the source is reliable. It is also easy for attackers to "spoof" email addresses, so verify that an email is legitimate before opening an unexpected email attachment or responding to a request for personal information (see Using Caution with Email Attachments and Avoiding Social Engineering and Phishing Attacks for more information).
If it sounds too good to be true, it probably is - You have probably seen many emails promising fantastic rewards or monetary gifts. However, regardless of what the email claims, there are not any wealthy strangers desperate to send you money. Beware of grand promises—they are most likely spam, hoaxes, or phishing schemes (see Reducing Spam, Identifying Hoaxes and Urban Legends, and Avoiding Social Engineering and Phishing Attacks for more information). Also be wary of pop-up windows and advertisements for free downloadable software—they may be disguising spyware (see Recognizing and Avoiding Spyware for more information).
Don't advertise that you are away from home - Some email accounts, especially within an organization, offer a feature (called an autoresponder) that allows you to create an "away" message if you are going to be away from your email for an extended period of time. The message is automatically sent to anyone who emails you while the autoresponder is enabled. While this is a helpful feature for letting your contacts know that you will not be able to respond right away, be careful how you phrase your message. You do not want to let potential attackers know that you are not home, or, worse, give specific details about your location and itinerary. Safer options include phrases such as "I will not have access to email between [date] and [date]." If possible, also restrict the recipients of the message to people within your organization or in your address book. If your away message replies to spam, it only confirms that your email account is active. This may increase the amount of spam you receive (see Reducing Spam for more information).
Lock up your valuables - If an attacker is able to access your personal data, he or she may be able to compromise or steal the information. Take steps to protect this information by following good security practices (see the Cyber Security Tips index page for a list of relevant documents). Some of the most basic precautions include locking your computer when you step away; using firewalls, anti-virus software, and strong passwords; installing appropriate patches; and taking precautions when browsing or using email.
Have a backup plan - Since your information could be lost or compromised (due to an equipment malfunction, an error, or an attack), make regular backups of your information so that you still have clean, complete copies (see Good Security Habits for more information). Backups also help you identify what has been changed or lost. If your computer has been infected, it is important to remove the infection before resuming your work (see Recovering from Viruses, Worms, and Trojan Horses for more information). Keep in mind that if you did not realize that your computer was infected, your backups may also be compromised.

Authors: Mindi McDowell, Matt Lytle

Safeguarding Your Data

2008-12-06T17:43:00.000+03:00

When there are multiple people using your computer and/or you store sensitive personal and work-related data on your computer, it is especially important to take extra security precautions.

Why isn't "more" better?

Maybe there is an extra software program included with a program you bought. Or perhaps you found a free download online. You may be tempted to install the programs just because you can, or because you think you might use them later. However, even if the source and the software are legitimate, there may be hidden risks. And if other people use your computer, there are additional risks.

These risks become especially important if you use your computer to manage your personal finances (banking, taxes, online bill payment, etc.), store sensitive personal data, or perform work-related activities away from the office. However, there are steps you can take to protect yourself.

How can you protect both your personal and work-related data?

Use and maintain anti-virus software and a firewall - Protect yourself against viruses and Trojan horses that may steal or modify the data on your own computer and leave you vulnerable by using anti-virus software and a firewall (see Understanding Anti-Virus Software and Understanding Firewalls for more information). Make sure to keep your virus definitions up to date.
Regularly scan your computer for spyware - Spyware or adware hidden in software programs may affect the performance of your computer and give attackers access to your data. Use a legitimate anti-spyware program to scan your computer and remove any of these files (see Recognizing and Avoiding Spyware for more information).
Keep software up to date - Install software patches so that attackers cannot take advantage of known problems or vulnerabilities (see Understanding Patches for more information). Many operating systems offer automatic updates. If this option is available, you should turn it on.
Evaluate your software's settings - The default settings of most software enable all available functionality. However, attackers may be able to take advantage of this functionality to access your computer. It is especially important to check the settings for software that connects to the internet (browsers, email clients, etc.). Apply the highest level of security available that still gives you the functionality you need.
Avoid unused software programs - Do not clutter your computer with unnecessary software programs. If you have programs on your computer that you do not use, consider uninstalling them.
Consider creating separate user accounts - If there are other people using your computer, you may be worried that someone else may accidentally access, modify, and/or delete your files. Most operating systems (including Windows XP, Mac OS X, and Linux) give you the option of creating a different user account for each user, and you can set the amount of access and privileges for each account. You may also choose to have separate accounts for your work and personal purposes. While this approach will not completely isolate each area, it does offer some additional protection.
Establish guidelines for computer use - If there are multiple people using your computer, especially children, make sure they understand how to use the computer and internet safely. Setting boundaries and guidelines will help to protect your data (see Keeping Children Safe Online for more information).
Use passwords and encrypt sensitive files - Passwords and other security features add layers of protection if used appropriately (see Choosing and Protecting Passwords and Supplementing Passwords for more information). By encrypting files, you ensure that unauthorized people can't view data even if they can physically access it. You may also want to consider options for full disk encryption, which prevents a thief from even starting your laptop without a passphrase. When you use encryption, it is important to remember your passwords and passphrases; if you forget or lose them, you may lose your data.
Follow corporate policies for handling and storing work-related information - If you use your computer for work-related purposes, make sure to follow any corporate policies for handling and storing the information. These policies were likely established to protect proprietary information and customer data, as well as to protect you and the company from liability.
Dispose of sensitive information properly - Simply deleting a file does not completely erase it. To ensure that an attacker cannot access these files, make sure that you adequately erase sensitive files (see Effectively Erasing Files for more information).
Follow good security habits - Review other security tips for ways to protect yourself and your data.

Author: Mindi McDowell

Good Security Habits

2008-12-06T17:42:00.002+03:00

There are some simple habits you can adopt that, if performed consistently, may dramatically reduce the chances that the information on your computer will be lost or corrupted.

How can you minimize the access other people have to your information?

You may be able to easily identify people who could, legitimately or not, gain physical access to your computer—family members, roommates, co-workers, members of a cleaning crew, and maybe others. Identifying the people who could gain remote access to your computer becomes much more difficult. As long as you have a computer and connect it to a network, you are vulnerable to someone or something else accessing or corrupting your information; however, you can develop habits that make it more difficult.

Lock your computer when you are away from it. Even if you only step away from your computer for a few minutes, it's enough time for someone else to destroy or corrupt your information. Locking your computer prevents another person from being able to simply sit down at your computer and access all of your information.
Disconnect your computer from the Internet when you aren't using it. The development of technologies such as DSL and cable modems have made it possible for users to be online all the time, but this convenience comes with risks. The likelihood that attackers or viruses scanning the network for available computers will target your computer becomes much higher if your computer is always connected. Depending on what method you use to connect to the Internet, disconnecting may mean ending a dial-up connection, turning off your computer or modem, or disconnecting cables.
Evaluate your security settings. Most software, including browsers and email programs, offers a variety of features that you can tailor to meet your needs and requirements. Enabling certain features to increase convenience or functionality may leave you more vulnerable to being attacked. It is important to examine the settings, particularly the security settings, and select options that meet your needs without putting you at increased risk. If you install a patch or a new version of the software, or if you hear of something that might affect your settings, reevaluate your settings to make sure they are still appropriate (see Understanding Patches, Safeguarding Your Data, and Evaluating Your Web Browser's Security Settings for more information).

What other steps can you take?

Sometimes the threats to your information aren't from other people but from natural or technological causes. Although there is no way to control or prevent these problems, you can prepare for them and try to minimize the damage.

Protect your computer against power surges. Aside from providing outlets to plug in your computer and all of its peripherals, some power strips protect your computer against power surges. Many power strips now advertise compensation if they do not effectively protect your computer. During a lightning storm or construction work that increases the odds of power surges, consider shutting your computer down and unplugging it from all power sources. Power strips alone will not protect you from power outages, but there are products that do offer an uninterruptible power supply when there are power surges or outages.
Back up all of your data. Whether or not you take steps to protect yourself, there will always be a possibility that something will happen to destroy your data. You have probably already experienced this at least once— losing one or more files due to an accident, a virus or worm, a natural event, or a problem with your equipment. Regularly backing up your data on a CD or network reduces the stress and other negative consequences that result from losing important information (see Real-World Warnings Keep You Safe Online for more information). Determining how often to back up your data is a personal decision. If you are constantly adding or changing data, you may find weekly backups to be the best alternative; if your content rarely changes, you may decide that your backups do not need to be as frequent. You don't need to back up software that you own on CD-ROM or DVD-ROM—you can reinstall the software from the original media if necessary.

Both the National Cyber Security Alliance and US-CERT have identified this topic as one of the top tips for home users.

Authors: Mindi McDowell, Allen Householder

Debunking Some Common Myths

2008-12-06T17:42:00.001+03:00

There are some common myths that may influence your online security practices. Knowing the truth will allow you to make better decisions about how to protect yourself.

How are these myths established?

There is no one cause for these myths. They may have been formed because of a lack of information, an assumption, knowledge of a specific case that was then generalized, or some other source. As with any myth, they are passed from one individual to another, usually because they seem legitimate enough to be true.

Why is it important to know the truth?

While believing these myths may not present a direct threat, they may cause you to be more lax about your security habits. If you are not diligent about protecting yourself, you may be more likely to become a victim of an attack.

What are some common myths, and what is the truth behind them?

Myth: Anti-virus software and firewalls are 100% effective.
Truth: Anti-virus software and firewalls are important elements to protecting your information (see Understanding Anti-Virus Software and Understanding Firewalls for more information). However, neither of these elements are guaranteed to protect you from an attack. Combining these technologies with good security habits is the best way to reduce your risk.

Myth: Once software is installed on your computer, you do not have to worry about it anymore.
Truth: Vendors may release patches or updated versions of software to address problems or fix vulnerabilities (see Understanding Patches for more information). You should install the patches as soon as possible; some software even offers the option to obtain updates automatically. Making sure that you have the latest virus definitions for your anti-virus software is especially important.

Myth: There is nothing important on your machine, so you do not need to protect it.
Truth: Your opinion about what is important may differ from an attacker's opinion. If you have personal or financial data on your computer, attackers may be able to collect it and use it for their own financial gain. Even if you do not store that kind of information on your computer, an attacker who can gain control of your computer may be able to use it in attacks against other people (see Understanding Denial-of-Service Attacks and Understanding Hidden Threats: Rootkits and Botnets for more information).

Myth: Attackers only target people with money.
Truth: Anyone can become a victim of identity theft. Attackers look for the biggest reward for the least amount of effort, so they typically target databases that store information about many people. If your information happens to be in the database, it could be collected and used for malicious purposes. It is important to pay attention to your credit information so that you can minimize any potential damage (see Preventing and Responding to Identity Theft for more information).

Myth: When computers slow down, it means that they are old and should be replaced.
Truth: It is possible that running newer or larger software programs on an older computer could lead to slow performance, but you may just need to replace or upgrade a particular component (memory, operating system, CD or DVD drive, etc.). Another possibility is that there are other processes or programs running in the background. If your computer has suddenly become slower, you may be experiencing a denial-of-service attack or have spyware on your machine (see Understanding Denial-of-Service Attacks and Recognizing and Avoiding Spyware for more information).

Author: Mindi McDowell

Coordinating Virus and Spyware Defense

2008-12-06T17:41:00.000+03:00

Using anti-virus and anti-spyware software is an important part of cyber security. But in an attempt to protect yourself, you may unintentionally cause problems.

Isn't it better to have more protection?

Spyware and viruses can interfere with your computer's ability to process information or can modify or destroy data. You may feel that the more anti-virus and anti-spyware programs you install on your computer, the safer you will be. It is true that not all programs are equally effective, and they will not all detect the same malicious code. However, by installing multiple programs in an attempt to catch everything, you may introduce problems.

How can anti-virus or anti-spyware software cause problems?

It is important to use anti-virus and anti-spyware software (see Understanding Anti-Virus Software and Recognizing and Avoiding Spyware for more information). But too much or the wrong kind can affect the performance of your computer and the effectiveness of the software itself.

Scanning your computer for viruses and spyware uses some of the available memory on your computer. If you have multiple programs trying to scan at the same time, you may limit the amount of resources left to perform your tasks. Essentially, you have created a denial of service against yourself (see Understanding Denial-of-Service Attacks for more information). It is also possible that in the process of scanning for viruses and spyware, anti-virus or anti-spyware software may misinterpret the virus definitions of other programs. Instead of recognizing them as definitions, the software may interpret the definitions as actual malicious code. Not only could this result in false positives for the presence of viruses or spyware, but the anti-virus or anti-spyware software may actually quarantine or delete the other software.

How can you avoid these problems?

Investigate your options in advance - Research available anti-virus and anti-spyware software to determine the best choice for you. Consider the amount of malicious code the software recognizes, and try to find out how frequently the virus definitions are updated. Also check for known compatibility issues with other software you may be running on your computer.
Limit the number of programs you install - Many vendors are now releasing packages that incorporate both anti-virus and anti-spyware capabilities together. However, if you decide to choose separate programs, you really only need one anti-virus program and one anti-spyware program. If you install more, you increase your risk for problems.
Install the software in phases - Install the anti-virus software first and test it for a few days before installing anti-spyware software. If problems develop, you have a better chance at isolating the source and then determining if it is an issue with the software itself or with compatibility.
Watch for problems - If your computer starts processing requests more slowly, you are seeing error messages when updating your virus definitions, your software does not seem to be recognizing malicious code, or other issues develop that cannot be easily explained, check your anti-virus and anti-spyware software.

Authors: Mindi McDowell, Matt Lytle

Understanding Firewalls

2008-12-06T17:40:00.000+03:00

When anyone or anything can access your computer at any time, your computer is more susceptible to being attacked. You can restrict outside access to your computer and the information on it with a firewall.

What do firewalls do?

Firewalls provide protection against outside attackers by shielding your computer or network from malicious or unnecessary Internet traffic. Firewalls can be configured to block data from certain locations while allowing the relevant and necessary data through (see Understanding Denial-of-Service Attacks and Understanding Hidden Threats: Rootkits and Botnets for more information). They are especially important for users who rely on "always on" connections such as cable or DSL modems.

What type of firewall is best?

Firewalls are offered in two forms: hardware (external) and software (internal). While both have their advantages and disadvantages, the decision to use a firewall is far more important than deciding which type you use.

Hardware - Typically called network firewalls, these external devices are positioned between your computer or network and your cable or DSL modem. Many vendors and some Internet Service Providers (ISPs) offer devices called "routers" that also include firewall features. Hardware-based firewalls are particularly useful for protecting multiple computers but also offer a high degree of protection for a single computer. If you only have one computer behind the firewall, or if you are certain that all of the other computers on the network are up to date on patches are free from viruses, worms, or other malicious code, you may not need the extra protection of a software firewall. Hardware-based firewalls have the advantage of being separate devices running their own operating systems, so they provide an additional line of defense against attacks. Their major drawback is cost, but many products are available for less than $100 (and there are even some for less than $50).
Software - Some operating systems include a built-in firewall; if yours does, consider enabling it to add another layer of protection even if you have an external firewall. If you don't have a built-in firewall, you can obtain a software firewall for relatively little or no cost from your local computer store, software vendors, or ISP. Because of the risks associated with downloading software from the Internet onto an unprotected computer, it is best to install the firewall from a CD, DVD, or floppy disk. Although relying on a software firewall alone does provide some protection, realize that having the firewall on the same computer as the information you're trying to protect may hinder the firewall's ability to catch malicious traffic before it enters your system.

How do you know what configuration settings to apply?

Most commercially available firewall products, both hardware- and software-based, come configured in a manner that is acceptably secure for most users. Since each firewall is different, you'll need to read and understand the documentation that comes with it in order to determine whether or not the default settings on your firewall are sufficient for your needs. Additional assistance may be available from your firewall vendor or your ISP (either from tech support or a web site). Also, alerts about current viruses or worms (such as US-CERT's Cyber Security Alerts) sometimes include information about restrictions you can implement through your firewall.

Unfortunately, while properly configured firewalls may be effective at blocking some attacks, don't be lulled into a false sense of security. Although they do offer a certain amount of protection, firewalls do not guarantee that your computer will not be attacked. In particular, a firewall offers little to no protection against viruses that work by having you run the infected program on your computer, as many email-borne viruses do. However, using a firewall in conjunction with other protective measures (such as anti-virus software and "safe" computing practices) will strengthen your resistance to attacks (see Understanding Anti-Virus Software and other security tips for more information).

Both the National Cyber Security Alliance and US-CERT have identified this topic as one of the top tips for home users.

Authors: Mindi McDowell, Allen Householder

Understanding Anti-Virus Software

2008-12-06T08:51:00.000+03:00

Anti-virus software can identify and block many viruses before they can infect your computer. Once you install anti-virus software, it is important to keep it up to date.

What does anti-virus software do?

Although details may vary between packages, anti-virus software scans files or your computer's memory for certain patterns that may indicate an infection. The patterns it looks for are based on the signatures, or definitions, of known viruses. Virus authors are continually releasing new and updated viruses, so it is important that you have the latest definitions installed on your computer.

Once you have installed an anti-virus package, you should scan your entire computer periodically.

Automatic scans - Depending what software you choose, you may be able to configure it to automatically scan specific files or directories and prompt you at set intervals to perform complete scans.
Manual scans - It is also a good idea to manually scan files you receive from an outside source before opening them. This includes

saving and scanning email attachments or web downloads rather than selecting the option to open them directly from the source
scanning media, including CDs and DVDs, for viruses before opening any of the files

What happens if the software finds a virus?

Each package has its own method of response when it locates a virus, and the response may differ according to whether the software locates the virus during an automatic or a manual scan. Sometimes the software will produce a dialog box alerting you that it has found a virus and asking whether you want it to "clean" the file (to remove the virus). In other cases, the software may attempt to remove the virus without asking you first. When you select an anti-virus package, familiarize yourself with its features so you know what to expect.

Which software should you use?

There are many vendors who produce anti-virus software, and deciding which one to choose can be confusing. All anti-virus software performs the same function, so your decision may be driven by recommendations, particular features, availability, or price. See the references section for a link to a list of some anti-virus vendors.

Installing any anti-virus software, regardless of which package you choose, increases your level of protection. Be careful, though, of email messages claiming to include anti-virus software. Some recent viruses arrive as an email supposedly from your ISP's technical support department, containing an attachment that claims to be anti-virus software. However, the attachment itself is in fact a virus, so you could become infected by opening it (see Using Caution with Email Attachments for more information).

How do you get the current virus information?

This process may differ depending what product you choose, so find out what your anti-virus software requires. Many anti-virus packages include an option to automatically receive updated virus definitions. Because new information is added frequently, it is a good idea to take advantage of this option. Resist believing email chain letters that claim that a well-known anti-virus vendor has recently detected the "worst virus in history" that will destroy your computer's hard drive. These emails are usually hoaxes (see Identifying Hoaxes and Urban Legends for more information). You can confirm virus information through your anti-virus vendor or through resources offered by other anti-virus vendors. See the references section for a link to some of these resources.

While installing anti-virus software is one of the easiest and most effective ways to protect your computer, it has its limitations. Because it relies on signatures, anti-virus software can only detect viruses that have signatures installed on your computer, so it is important to keep these signatures up to date. You will still be susceptible to viruses that circulate before the anti-virus vendors add their signatures, so continue to take other safety precautions as well.

Both the National Cyber Security Alliance and US-CERT have identified this topic as one of the top tips for home users.

Authors: Mindi McDowell, Allen Householder

Understanding Internet Service Providers (ISPs)

2008-12-06T08:50:00.001+03:00

ISPs offer services like email and internet access. Compare factors like security, services, and cost so that you find an ISP that supports all of your needs.

What is an ISP?

An ISP, or internet service provider, is a company that provides its customers access to the internet and other web services. In addition to maintaining a direct line to the internet, the company usually maintains web servers. By supplying necessary software, a password-protected user account, and a way to connect to the internet (e.g., modem, phone number), ISPs offer their customers the capability to browse the web and exchange email with other people. Some ISPs also offer additional services.

ISPs can vary in size—some are operated by one individual, while others are large corporations. They may also vary in scope—some only support users in a particular city, while others have regional or national capabilities.

What services do ISPs provide?

Almost all ISPs offer email and web browsing capabilities. They also offer varying degrees of user support, usually in the form of an email address or customer support hotline. Most ISPs also offer web hosting capabilities, allowing users to create and maintain personal web pages; and some may even offer the service of developing the pages for you. Many ISPs offer the option of high-speed access through DSL or cable modems, and some still offer dial-up connections.

As part of normal operation, most ISPs perform backups of email and web files. If the ability to recover email and web files is important to you, check with your ISP to see if they back up the data; it might not be advertised as a service. Additionally, some ISPs may implement firewalls to block some incoming traffic, although you should consider this a supplement to your own security precautions, not a replacement.

How do you choose an ISP?

There are thousands of ISPs, and it's often difficult to decide which one best suits your needs. Some factors to consider include

security - Do you feel that the ISP is concerned about security? Does it use encryption and SSL (see Protecting Your Privacy for more information) to protect any information you submit (e.g., user name, password)?
privacy - Does the ISP have a published privacy policy? Are you comfortable with who has access to your information and how it is being handled and used?
services - Does your ISP offer the services you want? Do they meet your requirements? Is there adequate support for the services?
cost - Are the ISP's costs affordable? Are they reasonable for the number of services you receive, as well as the level of those services? Are you sacrificing quality and security to get the lowest price?
reliability - Are the services your ISP provides reliable, or are they frequently unavailable due to maintenance, security problems, a high volume of users, or other reasons? If the ISP knows that services will be unavailable for a particular reason, does it adequately communicate that information?
user support - Are there published methods for contacting customer support? Do you receive prompt and friendly service? Do their hours of availability accommodate your needs? Do the consultants have the appropriate level of knowledge?
speed - How fast is your ISP's connection? Is it sufficient for accessing your email or navigating the internet?
recommendations - Have you heard or seen positive reviews about the ISP? Were they from trusted sources? Does the ISP serve your geographic area? If you've uncovered negative points, are they factors you are concerned about?

Author: Mindi McDowell

Guidelines for Publishing Information Online

2008-12-06T08:46:00.000+03:00

Remember that the internet is a public resource. Avoid putting anything online that you don't want the public to see or that you may want to retract.

Why is it important to remember that the internet is public?

Because the internet is so accessible and contains a wealth of information, it has become a popular resource for communicating, for researching topics, and for finding information about people. It may seem less intimidating than actually interacting with other people because there is a sense of anonymity. However, you are not really anonymous when you are online, and it is just as easy for people to find information about you as it is for you to find information about them. Unfortunately, many people have become so familiar and comfortable with the internet that they may adopt practices that make them vulnerable. For example, although people are typically wary of sharing personal information with strangers they meet on the street, they may not hesitate to post that same information online. Once it is online, it can be accessed by a world of strangers, and you have no idea what they might do with that information.

What guidelines can you follow when publishing information on the internet?

View the internet as a novel, not a diary - Make sure you are comfortable with anyone seeing the information you put online. Expect that people you have never met will find your page; even if you are keeping an online journal or blog, write it with the expectation that it is available for public consumption. Some sites may use passwords or other security restrictions to protect the information, but these methods are not usually used for most web sites. If you want the information to be private or restricted to a small, select group of people, the internet is probably not the best forum.
Be careful what you advertise - In the past, it was difficult to find information about people other than their phone numbers or address. Now, an increasing amount of personal information is available online, especially because people are creating personal web pages with information about themselves. When deciding how much information to reveal, realize that you are broadcasting it to the world. Supplying your email address may increase the amount of spam you receive (see Reducing Spam for more information). Providing details about your hobbies, your job, your family and friends, and your past may give attackers enough information to perform a successful social engineering attack (see Avoiding Social Engineering and Phishing Attacks for more information).
Realize that you can't take it back - Once you publish something online, it is available to other people and to search engines. You can change or remove information after something has been published, but it is possible that someone has already seen the original version. Even if you try to remove the page(s) from the internet, someone may have saved a copy of the page or used excerpts in another source. Some search engines "cache" copies of web pages so that they open faster; these cached copies may be available after a web page has been deleted or altered. Some web browsers may also maintain a cache of the web pages a user has visited, so the original version may be stored in a temporary file on the user's computer. Think about these implications before publishing information—once something is out there, you can't guarantee that you can completely remove it.

As a general practice, let your common sense guide your decisions about what to post online. Before you publish something on the internet, determine what value it provides and consider the implications of having the information available to the public. Identity theft is an increasing problem, and the more information an attacker can gather about you, the easier it is to pretend to be you. Behave online the way you would behave in your daily life, especially when it involves taking precautions to protect yourself.

Authors: Mindi McDowell, Matt Lytle, Jason Rafail

Understanding Patches

2008-12-04T10:15:00.000+03:00

When vendors become aware of vulnerabilities in their products, they often issue patches to fix the problem. Make sure to apply relevant patches to your computer as soon as possible so that your system is protected.

What are patches?

Similar to the way fabric patches are used to repair holes in clothing, software patches repair holes in software programs. Patches are updates that fix a particular problem or vulnerability within a program. Sometimes, instead of just releasing a patch, vendors will release an upgraded version of their software, although they may refer to the upgrade as a patch.

How do you find out what patches you need to install?

When patches are available, vendors usually put them on their web sites for users to download. It is important to install a patch as soon as possible to protect your computer from attackers who would take advantage of the vulnerability. Some software will automatically check for updates, and many vendors offer users the option to receive automatic notification of updates through a mailing list. If these automatic options are available, we recommend that you take advantage of them. If they are not available, check your vendors' web sites periodically for updates.

Make sure that you only download software or patches from web sites that you trust. Do not trust a link in an email message—attackers have used email messages to direct users to malicious web sites where users install viruses disguised as patches. Also, beware of email messages that claim that they have attached the patch to the message—these attachments are often viruses.

Both the National Cyber Security Alliance and US-CERT have identified this topic as one of the top tips for home users.

Author: Mindi McDowell

Understanding Your Computer: Web Browsers

2008-12-04T10:14:00.000+03:00

Web browsers allow you to navigate the internet. There are a variety of options available, so you can choose the one that best suits your needs.

How do web browsers work?

A web browser is an application that finds and displays web pages. It coordinates communication between your computer and the web server where a particular web site "lives."

When you open your browser and type in a web address (URL) for a web site, the browser contacts that server, requests the web page you asked for, and displays the page on your computer. The browser translates the code (written in a language such as HTML or XML) for the different elements of the page (text, images, sounds) into the appropriate format and displays the resulting page.

How many browsers are there?

There are many different browsers. Most users are familiar with graphical browsers, which display both text and graphics and may also display multimedia elements such as sound or video clips. However, there are also text-based browsers. The following are some well-known browsers:

Internet Explorer
Firefox
AOL
Opera
Safari - a browser specifically designed for Macintosh computers
Lynx - a text-based browser desirable for vision-impaired users because of the availability of special devices that read the text

How do you choose a browser?

A browser is usually included with the installation of your operating system, but you are not restricted to that choice. Some of the factors to consider when deciding which browser best suits your needs include

compatibility - Does the browser work with your operating system?
security - Do you feel that your browser offers you the level of security you want?
ease of use - Are the menus and options easy to understand and use?
functionality - Does the browser interpret web content correctly? If you need to install other plug-ins or devices to translate certain types of content, do they work?
appeal - Do you find the interface and way the browser interprets web content visually appealing?

Can you have more than one browser installed at the same time?

If you decide to change your browser or add another one, you don't have to uninstall the browser that's currently on your computer—you can have more than one browser on your computer at once. However, you will be prompted to choose one as your default browser. Anytime you follow a link in an email message or document, or you double-click a shortcut to a web page on your desktop, the page will open using your default browser. You can manually open the page in another browser.

Most vendors give you the option to download their browsers directly from their web sites. Make sure to verify the authenticity of the site before downloading any files. To further minimize risk, follow other good security practices, like using a firewall and keeping anti-virus software up to date (see Understanding Firewalls, Understanding Anti-Virus Software, and other US-CERT Cyber Security Tips for more information).

Author: Mindi McDowell

How Anonymous Are You?

2008-12-04T10:01:00.000+03:00

You may think that you are anonymous as you browse web sites, but pieces of information about you are always left behind. You can reduce the amount of information revealed about you by visiting legitimate sites, checking privacy policies, and minimizing the amount of personal information you provide.

What information is collected?

When you visit a web site, a certain amount of information is automatically sent to the site. This information may include the following:

IP address - Each computer on the internet is assigned a specific, unique IP (internet protocol) address. Your computer may have a static IP address or a dynamic IP address. If you have a static IP address, it never changes. However, some ISPs own a block of addresses and assign an open one each time you connect to the internet—this is a dynamic IP address. You can determine your computer's IP address at any given time by visiting www.showmyip.com
domain name - The internet is divided into domains, and every user's account is associated with one of those domains. You can identify the domain by looking at the end of URL; for example, .edu indicates an educational institution, .gov indicates a US government agency, .org refers to organization, and .com is for commercial use. Many countries also have specific domain names. The list of active domain names is available from the Internet Assigned Numbers Authority (IANA).
software details - It may be possible for an organization to determine which browser, including the version, that you used to access its site. The organization may also be able to determine what operating system your computer is running.
page visits - Information about which pages you visited, how long you stayed on a given page, and whether you came to the site from a search engine is often available to the organization operating the web site.

If a web site uses cookies, the organization may be able to collect even more information, such as your browsing patterns, which include other sites you've visited. If the site you're vising is malicious, files on your computer, as well as passwords stored in the temporary memory, may be at risk.

How is this information used?

Generally, organizations use the information that is gathered automatically for legitimate purposes, such as generating statistics about their sites. By analyzing the statistics, the organizations can better understand the popularity of the site and which areas of content are being accessed the most. They may be able to use this information to modify the site to better support the behavior of the people visiting it.

Another way to apply information gathered about users is marketing. If the site uses cookies to determine other sites or pages you have visited, it may use this information to advertise certain products. The products may be on the same site or may be offered by partner sites.

However, some sites may collect your information for malicious purposes. If attackers are able to access files, passwords, or personal information on your computer, they may be able to use this data to their advantage. The attackers may be able to steal your identity, using and abusing your personal information for financial gain. A common practice is for attackers to use this type of information once or twice, then sell or trade it to other people. The attackers profit from the sale or trade, and increasing the number of transactions makes it more difficult to trace any activity back to them. The attackers may also alter the security settings on your computer so that they can access and use your computer for other malicious activity.

Are you exposing any other personal information?

While using cookies may be one method for gathering information, the easiest way for attackers to get access to personal information is to ask for it. By representing a malicious site as a legitimate one, attackers may be able to convince you to give them your address, credit card information, social security number, or other personal data (see Avoiding Social Engineering and Phishing Attacks for more information).

How can you limit the amount of information collected about you?

Be careful supplying personal information - Unless you trust a site, don't give your address, password, or credit card information. Look for indications that the site uses SSL to encrypt your information (see Protecting Your Privacy for more information). Although some sites require you to supply your social security number (e.g., sites associated with financial transactions such as loans or credit cards), be especially wary of providing this information online.
Limit cookies - If an attacker can access your computer, he or she may be able to find personal data stored in cookies. You may not realize the extent of the information stored on your computer until it is too late. However, you can limit the use of cookies (see Browsing Safely: Understanding Active Content and Cookies for more information).
Browse safely - Be careful which web sites you visit; if it seems suspicious, leave the site. Also make sure to take precautions by increasing your security settings (see Evaluating Your Web Browser's Security Settings for more information), keeping your virus definitions up to date (see Understanding Anti-Virus Software for more information), and scanning your computer for spyware (see Recognizing and Avoiding Spyware for more information).

Additional information

Securing Your Web Browser

Author: Mindi McDowell

Protecting Portable Devices: Physical Security

2008-12-04T09:58:00.000+03:00

Many computer users, especially those who travel for business, rely on laptops and PDAs because they are small and easily transported. But while these characteristics make them popular and convenient, they also make them an ideal target for thieves. Make sure to secure your portable devices to protect both the machine and the information it contains.

What is at risk?

Only you can determine what is actually at risk. If a thief steals your laptop or PDA, the most obvious loss is the machine itself. However, if the thief is able to access the information on the computer or PDA, all of the information stored on the device is at risk, as well as any additional information that could be accessed as a result of the data stored on the device itself.

Sensitive corporate information or customer account information should not be accessed by unauthorized people. You've probably heard news stories about organizations panicking because laptops with confidential information on them have been lost or stolen. But even if there isn't any sensitive corporate information on your laptop or PDA, think of the other information at risk: information about appointments, passwords, email addresses and other contact information, personal information for online accounts, etc.

How can you protect your laptop or PDA?

Password-protect your computer - Make sure that you have to enter a password to log in to your computer (see Choosing and Protecting Passwords for more information).
Keep your laptop or PDA with you at all times - When traveling, keep your laptop with you. Meal times are optimum times for thieves to check hotel rooms for unattended laptops. If you are attending a conference or trade show, be especially wary—these venues offer thieves a wider selection of devices that are likely to contain sensitive information, and the conference sessions offer more opportunities for thieves to access guest rooms.
Downplay your laptop or PDA - There is no need to advertise to thieves that you have a laptop or PDA. Avoid using your portable device in public areas, and consider non-traditional bags for carrying your laptop.
Consider an alarm or lock - Many companies sell alarms or locks that you can use to protect or secure your laptop. If you travel often or will be in a heavily populated area, you may want to consider investing in an alarm for your laptop bag or a lock to secure your laptop to a piece of furniture.
Back up your files - If your portable device is stolen, it's bad enough that someone else may be able to access your information. To avoid losing all of the information, make backups of important information and store the backups in a separate location (see Good Security Habits for more information). Not only will you still be able to access the information, but you'll be able to identify and report exactly what information is at risk.

What can you do if your laptop or PDA is lost or stolen?

Report the loss or theft to the appropriate authorities. These parties may include representatives from law enforcement agencies, as well as hotel or conference staff. If your device contained sensitive corporate or customer account information, immediately report the loss or theft to your organization so that they can act quickly.

Author: Mindi McDowell

Understanding Your Computer: Email Clients

2008-12-04T09:57:00.000+03:00

The main difference between email clients is the user interface. Regardless of which software you decide to use, follow good security practices when reading or sending email.

How do email clients work?

Every email address has two basic parts: the user name and the domain name. When you are sending email to someone else, your domain's server has to communicate with your recipient's domain server.

For example, let's assume that your email address is johndoe@example.com, and the person you are contacting is at janesmith@anotherexample.org. In very basic terms, after you hit send, the server hosting your domain (example.com) looks at the email address and then contacts the server hosting the recipient's domain (anotherexample.org) to let it know that it has a message for someone at that domain. Once the connection has been established, the server hosting the recipient's domain (anotherexample.org) then looks at the user name of the email address and routes the message to that account.

How many email clients are there?

There are many different email clients and services, each with its own interface. Some are web-based, some are stand-alone graphics-based, and some are text-based. The following are some well-known email programs:

Hotmail
Yahoo! Mail
Gmail

Stand-alone graphics-based

Outlook and Outlook Express
Thunderbird
Pegasus

Text-based

Pine

How do you choose an email client?

There is usually an email client included with the installation of your operating system, but many other alternatives are available. Be wary of "home-brewed" software, because it may not be as secure or reliable as software that is tested and actively maintained. Some of the factors to consider when deciding which email client best suits your needs include

security - Do you feel that your email program offers you the level of security you want for sending, receiving, and reading email messages? How does it handle attachments (see Using Caution with Email Attachments for more information)? If you are dealing with sensitive information, do you have the option of sending and receiving signed and/or encrypted messages (see Understanding Digital Signatures and Understanding Encryption for more information)?
privacy - If you are using a web-based service, have you read its privacy policy (see Protecting Your Privacy for more information)? Do you know what information is being collected and who has access to it? Are there options for filtering spam (see Reducing Spam for more information)?
functionality - Does the software send, receive, and interpret email messages appropriately?
reliability - For web-based services, is the server reliable, or is your email frequently unavailable due to maintenance, security problems, a high volume of users, or other reasons?
availability - Do you need to be able to access your account from any computer?
ease of use - Are the menus and options easy to understand and use?
visual appeal - Do you find the interface appealing?

Each email client may have a different way of organizing drafted, sent, saved, and deleted mail. Familiarize yourself with the software so that you can find and store messages easily, and so that you don't unintentionally lose messages. Once you have chosen the software you want to use for your email, protect yourself and your contacts by following good security practices (see US-CERT Cyber Security Tips for more information).

Can you have use more than one email client?

You can have more than one email client, although you may have issues with compatibility. Some email accounts, such as those issued through your internet service provider (ISP) or place of employment, are only accessible from a computer that has appropriate privileges and settings for you to access that account. You can use any stand-alone email client to read those messages, but if you have more than one client installed on your machine, you should choose one as your default. When you click an email link in a browser or email message, your computer will open that default email client that you chose.

Most vendors give you the option to download their email software directly from their web sites. Make sure to verify the authenticity of the site before downloading any files, and follow other good security practices, like using a firewall and keeping anti-virus software up to date, to further minimize risk (see Understanding Firewalls, Understanding Anti-Virus Software, and other US-CERT Cyber Security Tips for more information).

You can also maintain free email accounts through browser-based email clients (e.g., Yahoo!, Hotmail, Gmail) that you can access from any computer. Because these accounts are maintained directly on the vendors' servers, they don't interfere with other email accounts.

Author: Mindi McDowell

Dealing with Cyberbullies

2008-12-04T09:46:00.000+03:00

Bullies are now taking advantage of technology to intimidate and harass their victims. Dealing with cyberbullying can be difficult, but there are steps you can take.

What is cyberbullying?

Cyberbullying refers to the new, and growing, practice of using technology to harass, or bully, someone else. Bullies used to be restricted to methods such as physical intimidation, postal mail, or the telephone. Now, developments in electronic media offer forums such as email, instant messaging, web pages, and digital photos to add to the arsenal. Computers, cell phones, and PDAs are new tools that can be applied to an old practice.

Forms of cyberbullying can range in severity from cruel or embarrassing rumors to threats, harassment, or stalking. It can affect any age group; however, teenagers and young adults are common victims, and cyberbullying is a growing problem in schools.

Why has cyberbullying become such a problem?

The relative anonymity of the internet is appealing for bullies because it enhances the intimidation and makes tracing the activity more difficult. Some bullies also find it easier to be more vicious because there is no personal contact. Unfortunately, the internet and email can also increase the visibility of the activity. Information or pictures posted online or forwarded in mass emails can reach a larger audience faster than more traditional methods, causing more damage to the victims. And because of the amount of personal information available online, bullies may be able to arbitrarily choose their victims.

Cyberbullying may also indicate a tendency toward more serious behavior. While bullying has always been an unfortunate reality, most bullies grow out of it. Cyberbullying has not existed long enough to have solid research, but there is evidence that it may be an early warning for more violent behavior.

How can you protect yourself?

Be careful where you post personal information - By limiting the number of people who have access to your contact information or details about your interests, habits, or employment, you reduce your exposure to bullies that you do not know. This may limit your risk of becoming a victim and may make it easier to identify the bully if you are victimized.
Avoid escalating the situation - Responding with hostility is likely to provoke a bully and escalate the situation. Depending on the circumstances, consider ignoring the issue. Often, bullies thrive on the reaction of their victims. Other options include subtle actions. For example, if you are receiving unwanted email messages, consider changing your email address. If the bully does not have access to the new address, the problem may stop. If you continue to get messages at your new account, you may have a stronger case for legal action.
Document the activity - Keep a record of any online activity (emails, web pages, instant messages, etc.), including relevant dates and times. In addition to archiving an electronic version, consider printing a copy.
Report cyberbullying to the appropriate authorities - If you are being harassed or threatened, report the activity to the local authorities. Law enforcement agencies have different policies, but your local police department or FBI branch are good starting points. Unfortunately, there is a distinction between free speech and punishable offenses, but the legal implications should be decided by the law enforcement officials and the prosecutors. Depending on the activity, it may also be appropriate to report it to school officials who may have separate policies for dealing with activity that involves students.

Protect your children by teaching them good online habits (see Keeping Children Safe Online for more information). Keep lines of communication open with your children so that they feel comfortable telling you if they are being victimized online. Reduce their risk of becoming cyberbullies by setting guidelines for and monitoring their use of the internet and other electronic media (cell phones, PDAs, etc.).

Author: Mindi McDowell

Choosing and Protecting Passwords

2008-12-04T09:42:00.000+03:00

Passwords are a common form of authentication and are often the only barrier between a user and your personal information. There are several programs attackers can use to help guess or "crack" passwords, but by choosing good passwords and keeping them confidential, you can make it more difficult for an unauthorized person to access your information.

Why do you need a password?

Think about the number of PIN numbers, passwords, or passphrases you use every day: getting money from the ATM or using your debit card in a store, logging on to your computer or email, signing in to an online bank account or shopping cart...the list seems to just keep getting longer. Keeping track of all of the number, letter, and word combinations may be frustrating at times, and maybe you've wondered if all of the fuss is worth it. After all, what attacker cares about your personal email account, right? Or why would someone bother with your practically empty bank account when there are others with much more money? Often, an attack is not specifically about your account but about using the access to your information to launch a larger attack. And while having someone gain access to your personal email might not seem like much more than an inconvenience and threat to your privacy, think of the implications of an attacker gaining access to your social security number or your medical records.

One of the best ways to protect information or physical property is to ensure that only authorized people have access to it. Verifying that someone is the person they claim to be is the next step, and this authentication process is even more important, and more difficult, in the cyber world. Passwords are the most common means of authentication, but if you don't choose good passwords or keep them confidential, they're almost as ineffective as not having any password at all. Many systems and services have been successfully broken into due to the use of insecure and inadequate passwords, and some viruses and worms have exploited systems by guessing weak passwords.

How do you choose a good password?

Most people use passwords that are based on personal information and are easy to remember. However, that also makes it easier for an attacker to guess or "crack" them. Consider a four-digit PIN number. Is yours a combination of the month, day, or year of your birthday? Or the last four digits of your social security number? Or your address or phone number? Think about how easily it is to find this information out about somebody. What about your email password—is it a word that can be found in the dictionary? If so, it may be susceptible to "dictionary" attacks, which attempt to guess passwords based on words in the dictionary.

Although intentionally misspelling a word ("daytt" instead of "date") may offer some protection against dictionary attacks, an even better method is to rely on a series of words and use memory techniques, or mnemonics, to help you remember how to decode it. For example, instead of the password "hoops," use "IlTpbb" for "[I] [l]ike [T]o [p]lay [b]asket[b]all." Using both lowercase and capital letters adds another layer of obscurity. Your best defense, though, is to use a combination of numbers, special characters, and both lowercase and capital letters. Change the same example we used above to "Il!2pBb." and see how much more complicated it has become just by adding numbers and special characters.

Don't assume that now that you've developed a strong password you should use it for every system or program you log into. If an attacker does guess it, he would have access to all of your accounts. You should use these techniques to develop unique passwords for each of your accounts.

Here is a review of tactics to use when choosing a password:

Don't use passwords that are based on personal information that can be easily accessed or guessed
Don't use words that can be found in any dictionary of any language
Develop a mnemonic for remembering complex passwords
Use both lowercase and capital letters
Use a combination of letters, numbers, and special characters
Use different passwords on different systems

How can you protect your password?

Now that you've chosen a password that's difficult to guess, you have to make sure not to leave it someplace for people to find. Writing it down and leaving it in your desk, next to your computer, or, worse, taped to your computer, is just making it easy for someone who has physical access to your office. Don't tell anyone your passwords, and watch for attackers trying to trick you through phone calls or email messages requesting that you reveal your passwords.

If your Internet service provider (ISP) offers choices of authentication systems, look for ones that use Kerberos, challenge/response, or public key encryption rather than simple passwords (see Understanding ISPs and Supplementing Passwords for more information). Consider challenging service providers who only use passwords to adopt more secure methods.

Also, many programs offer the option of "remembering" your password, but these programs have varying degrees of security protecting that information. Some programs, such as email clients, store the information in clear text in a file on your computer. This means that anyone with access to your computer can discover all of your passwords and can gain access to your information. For this reason, always remember to log out when you are using a public computer (at the library, an Internet cafe, or even a shared computer at your office). Other programs, such as Apple's Keychain and Palm's Secure Desktop, use strong encryption to protect the information. These types of programs may be viable options for managing your passwords if you find you have too many to remember.

There's no guarantee that these techniques will prevent an attacker from learning your password, but they will make it more difficult.

Authors: Mindi McDowell, Jason Rafail, Shawn Hernan

Why is Cyber Security a Problem?

2008-12-04T09:36:00.000+03:00

You've heard the news stories about credit card numbers being stolen and email viruses spreading. Maybe you've even been a victim yourself. One of the best defenses is understanding the risks, what some of the basic terms mean, and what you can do to protect yourself against them.

What is cyber security?

It seems that everything relies on computers and the Internet now — communication (email, cellphones), entertainment (digital cable, mp3s), transportation (car engine systems, airplane navigation), shopping (online stores, credit cards), medicine (equipment, medical records), and the list goes on. How much of your daily life relies on computers? How much of your personal information is stored either on your own computer or on someone else's system?

Cyber security involves protecting that information by preventing, detecting, and responding to attacks.

What are the risks?

There are many risks, some more serious than others. Among these dangers are viruses erasing your entire system, someone breaking into your system and altering files, someone using your computer to attack others, or someone stealing your credit card information and making unauthorized purchases. Unfortunately, there's no 100% guarantee that even with the best precautions some of these things won't happen to you, but there are steps you can take to minimize the chances.

What can you do?

The first step in protecting yourself is to recognize the risks and become familiar with some of the terminology associated with them.

Hacker, attacker, or intruder

Malicious code - This category includes code such as viruses, worms, and Trojan horses. Although some people use these terms interchangeably, they have unique characteristics.

Viruses - This type of malicious code requires you to actually do something before it infects your computer. This action could be opening an email attachment or going to a particular web page.
Worms - Worms propagate without user intervention. They typically start by exploiting a software vulnerability (a flaw that allows the software's intended security policy to be violated), then once the victim computer has been infected the worm will attempt to find and infect other computers. Similar to viruses, worms can propagate via email, web sites, or network-based software. The automated self-propagation of worms distinguishes them from viruses.
Trojan horses - A Trojan horse program is software that claims to be one thing while in fact doing something different behind the scenes. For example, a program that claims it will speed up your computer may actually be sending confidential information to a remote intruder.

This series of information security tips will give you more information about how to recognize and protect yourself from attacks.

Authors: Mindi McDowell, Allen Householder

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2008-12-04T09:22:00.001+03:00

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