Spam, scams and shams... Computer Viruses

A guide to computer viruses and ways to avoid them

Author:  Tina Landers

We're all terrified of them, but what exactly is a computer virus?

As we've discussed elsewhere on this site, a computer program (or application) is a series of instructions. Depending on the nature of the application, the series may be comprised of thousands or even millions of instructions.

A computer virus is simply a program or a set of instructions that produce unwanted (usually damaging) results to and on a computer, usually without any intervention from the user. A virus is programmed to spread itself by attaching itself to other files and programs. It may also be programmed to modify itself along the way. It may spread itself when users inadvertantly share files and/or programs with others, or it may spread itself by "creating" infected files and sending them to other users using transfer mediums such as emails.

A computer virus fits into the software category generally referred to as "malware". Other forms of malware include trojan horses, worms, spyware, adware etc. Each of them has a different definition and meaning, though they all share the same characteristic of being unwanted programs.

Estimates put the number of different computer viruses in excess of a hundred and fifty thousand, with the number growing every day. Our widespread use of computer technology, in the form of the Internet, World Wide Web, Email etc has enabled computer viruses to thrive and proliferate.

A computer virus can be created and written by anyone with enough knowledge to write computer code. The reasons for someone writing such code are as varied as the viruses themselves. Think of computer viruses as graffiti (though far more damaging) and the virus writer as the graffiti artist. Why do they do it? Perhaps they see it as their "statement", who knows? Some viruses have been simple pranks that went horribly wrong. Regardless, creating and writing a computer virus is a criminal offence in most countries.

The effects of having your computer infected by a virus can be varied. Some viruses simply replicate themselves and spread without doing any permanent damage. Some attempt to "choke" computers and networks by causing a flurry of unnecessary activity. Some sit in RAM and intercept genuine program's instructions to produce confusing and unexpected results. Some use your email system to spread themselves by sending emails to all your contacts. Others can cause disaster by erasing files and/or the contents of Hard Disk Drives.

How do you avoid being infected? Have an anti-virus program active on your computer at all times. In fact, anti-virus software should be one of the first software packages you install on any new computer. If you don't have any virus protection, you should immediately get some. There are even free anti-virus software programs available over the Internet. The free versions offer only basic protection, but they're a good start if you have nothing. Of the free titles available, we suggest the Grisoft product AVG Anti Virus. You can find out more about it and download it here. If you'd like to know how to download and install software, you can read a more detailed article here.

Which anti-virus software do we use? We use and recommend McAfee Anti-virus. It's used by many large companies around the world and so is right up-to-date with the latest in anti-virus protection. After installing, it sits in the background quietly doing its job without interrupting us...just the way we like it. It also updates itself without any intervention from the user. Very convenient. It's also reasonably priced for the home user. You can find out more and get it here.

Now, just because you have an anti-virus program protecting you doesn't mean you're entirely safe. Virus writers continually try to find new ways to by-pass these programs. It really is a cat-and-mouse game. To help yourself, be aware and cautious of anything and everything you install and/or receive on your computer. Remember, unlike their biological namesake, computer viruses are not airborne, they have to somehow get into your computer through another file, program, email, CD, Floppy Disk, etc. If you have concerns about a particular file, again "scan" it using your anti-virus program. If you have concerns about a particular email attachment, don't open it.

So, how do you know if you have been infected by a computer virus? Well, if your computer starts behaving unexpectedly, be suspicious. It may not be a virus that's the problem, but it's far better to be safe than sorry. Immediately run your anti-virus program to "scan" your entire system. Yes, it takes a while, but again - better safe than sorry.

What do you do if you have a computer virus? First and foremost run your anti-virus program and follow its instructions. In most cases your anti-virus program will guide you through the steps to "quarantine" and/or "remove/delete" the infection. If the virus is particularly new and/or widespread throughout your computer, you may need to seek professional help. A good place to start is at the anti-virus developers' websites. You will find a wealth of information and help at these sites:

• McAfee
• Symantec
• Trend Micro
• CNET
• VirusList 
• Grisoft 
• Microsoft 

Windows XP provides a facility whereby your computer can be restored to an earlier point in time (assuming you know when your computer became infected). If you do restore to an earlier time, remember that all your work since that time will be lost.

In extreme cases, entire Hard Disk Drives have had to be professionally erased and everything re-installed from a Backup. You do backup your important files, don't you?

If you don't have any backup software, we use and recommend Zip Backup. You can find out more about it and/or trial it here.

How to find Windows XP's System Restore Facility

You can read a more detailed article about maintaining and cleaning your computer here.