"A parasitic program written intentionally to enter a computer without the user's permission or knowledge. The word parasitic is used because a virus attaches to files or boot sectors and replicates itself thus continuing to spread. Though some viruses do little but replicate, others can cause serious damage or affect program and system performance."

Viruses typically spread by email or floppy disk. Data files cannot transfer a virus by themselves. Only executable program files can transfer a virus or infect a system. However, it is also important to understand that Word or Excel macros are considered executable and can be infected. It's a good idea to disable macros on any document you receive from an outside source, at least until you've had a chance to check it for a virus. Macro viruses can often infect your other documents and destroy access to your data!

Why should I be cautious about viruses?

Viruses can cause numerous problems - they can degrade the performance of your computer, compromise the security of your computer, corrupt data and delete files. Because they are relatively easily transmitted over the Internet, as well as through disks, it's vitally important to make sure that your computer is protected.

What is the best way to prevent my computer from being infected?

There are several precautions that can be taken in order to minimize the risk of virus infection. One of the most important - and the simplest - is to make sure to use caution when running any program from somebody you don't know. This includes both attachments emailed to you, or those that are downloaded from the Internet. It's also good to be careful even when running something sent by a friend or acquaintance - sometimes they inadvertently may mail you a virus they accidentally triggered themselves.

Another good idea is to install a virus scanner on your computer. There are many good commercial anti-virus programs available at your local computer store, or from an online retailer. You may wish to check out Norton at www.symantec.com/nav/ or McAfee at www.mcafee.com. Both have well-known and respected anti-virus scanners. After you've installed your anti-virus software, it's also important to regularly update it for the most recent anti-virus data, and to make sure you do regular scans. Your anti-virus program will have more information!

Virus Hoax

Far more common than an actual virus is the virus hoax. While programming a virus takes a certain level of expertise, anyone can start a rumor. Hoaxes begin with an email warning dire consequences if the recipient receives an email message from a specified sender or with a particular subject line or some other description. The majority of these warnings are complete works of fiction. Even sophisticated computer professionals have been known to pass along hoaxes. Remember, it's impossible for pure text to transmit a virus. So any emails without attachments can not transmit a virus. Of course, it's always a good idea to treat any unknown program with caution! If you have any question about the truth of a virus warning you get, click here to check the Symantec Anti-Virus Hoax Page.

Other Common Hoaxes

Due in part to the fact that communication is so fast and inexpensive on the Internet, it has become a breeding ground for hoaxes and urban legends. One of the most common is the "get something for passing on this email" story. There are numerous variations, but the basic story is this: "Send this email to a bunch of your friends and you will get something. This is being done by a big computer company to test email tracking software." Some of the variations include a free Disney vacation, a nickel for every email you send, a donation to a child dying of leukemia, and others. These messages are always hoaxes. There is no practical way for AOL, Microsoft, Gateway, myVine.com, or any other company to track the recipients of all of the messages forwarded from a single originating email. There is also no good reason that any of those companies (or anyone else) would want to do so.


Sites of Interest
• Symantec
• Mcafee
• GetVirusHelp.com

Interested in learning more?

There are many useful sites out there with additional information about viruses. We've listed a few good ones below, in order to give you a starting place to research.

The National Institute of Standards and Technology:
http://csrc.ncsl.nist.gov/virus/

Oxford University:
http://www.oucs.ox.ac.uk/micros/prevent/viruses/

International Computer Security Association:
http://www.icsalabs.com/html/communities/antivirus/index.shtml

University of North Texas
http://cwn.unt.edu/virus/

A site at University of Wisconsin containing many additional links: http://www.bocklabs.wisc.edu/~janda/