The magazine of the Melbourne PC User Group
New to Computers?
 Are You Asking , "What Is a Computer Virus?"
Gary Taig
 garyt@melbpc.org.au

A virus is a program or script that runs on your computer. That's all computers do, they run programs; each program written to perform a specific task. A virus program will fall into one of three broad categories:
  • It can be a relatively harmless joke and do no real damage, or
  • It can cause you a lot of inconvenience and expense, or
  • It can create havoc on your system, destroying all your programs and data and in some cases, even render your machine useless.
The name virus was given to these programs a decade ago when they first appeared because they are written in such a way that they spread themselves around. A computer virus program can attach itself to an e-mail message or embed itself in documents, or write a copy of itself onto the boot sector of a disk, or hide itself on the end of an executable program that you might use frequently.
 
The vandals who write these virus programs use very clever ways to distribute their nasty payload and the worst part is that you know nothing about it. You do not know a virus is on your computer until either its damage becomes obvious, or you are otherwise alerted.

If a virus remains undetected on your machine for a period of time it can systematically destroy all your programs and data. You find out when it's too late, when your computer and/or programs stop working.

Usually the virus must be activated. That is, you have to do something that causes the program to run, like clicking on an icon. Recently though, some virus writers have overcome that obstacle - some of the virus programs embedded in e-mail messages can be run upon receipt, automatically activated by smart "features" built into the more popular Internet software packages.

In recent times we have also seen some really nasty hoaxes perpetrated on the computing public. If you receive an e-mail message telling you to look for a particular file on your machine, telling you that the file is a virus and to delete it immediately, and then to warn all your friends and contacts... it is almost certainly a hoax. The file you are asked to delete will be part of your operating system or part of a legitimate software package. The sick minds that dream up these hoaxes are just as bad as the virus programmers, although undoubtedly not as talented.

As a computer user you have no choice but to arm yourself with knowledge about how to avoid virus programs and above all, stay up to date. In this issue Michael Mullerworth has written two excellent articles on the subject. For newcomers to computing, Michael's articles are highly recommended reading at http://www.melbpc.org.au/pcupdate/2205/2205article6.htm and http://www.melbpc.org.au/pcupdate/2205/2205article7.htm

Reprinted from the June 2002 issue of PC Update, the magazine of Melbourne PC User Group, Australia

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