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Anti-virus Software Basics
Author: Craig "hachiroku" Mercer
Date Created:2003-03-25
Operating System(s):Windows Logo imageWindows 9X/2000/XP
MacOS Logo imageMacOS

What is a computer virus?
A virus is any code or software that runs on a computer unbeknownst by the owner and causes damage. It may come in a number of forms such as, trojans, macros, and worms.

Trojans: a program that appears to be legitimate but is designed to have negative effects on the computer onto which the program was loaded.

Macros: a computer virus which is embedded into a document or application (like MS Word, Excel) and all future documents are also infected until the macro is removed.

Worms: a malicious program that replicates itself until it fills all of the available space on a hard drive.

How do you stop a virus?
Step 1) First you need to purchase and install some anti-virus software. There are numerous anti-virus software companies out there and each have their own merits. Following is a short list of some of the larger anti-virus vendors:

Step 2) Next you need to configure the software to protect your computer. Most "off the shelf" products will configure "by default" to auto-protect your hard disk and to scan incoming/outgoing email for viruses.
Note: Remember that scanning for viruses in real-time may cause a significant decrease in system performance.

Step 3) Finally you need to ensure that the software is updating the virus definition files daily. Definition files are usually downloaded online from a server at the software manufacturer. All anti-virus software depends on its' definition files to determine whether or not a particular piece of software may be infected. As a file comes into your computer, the anti-virus software will scan it for known types of viruses, the known types are found in the definition files. To illustrate this point, we'll look at Norton Anti-Virus

Norton Virus Definitions