Anti-virus

Probably one of the most talked about problems when computers are discussed is that of viruses. Unfortunately, they are everywhere on the Internet! Here are some handy hints that will ensure that contracting a virus is the exception and not the norm.

What is a virus?
How does my computer get a virus?
How do I know if my computer has a virus?
Anti-virus software
Tips on helping to prevent your computer from becoming infected with viruses

What is a virus?

A virus is a small program or routine that is designed to find its way into computers and disrupt the way they work. One theory about why people write these viruses is that they enjoy having power over other people’s computers on a huge scale - it makes them a kind of computer world dictator! Another is that people just like showing off to the world that they can write viruses which get into your computer.

There are two main types of virus:

• ones that you download onto your computer unknowingly, believing that they are a piece of free software or an attachment in an email;
• ones that piggy-back another file, where the virus has embedded or infected itself into a file that usually has nothing to do with the creator of the virus.

How does my computer get a virus?

A virus has to be put on your machine from somewhere else. In the distant past, before the Internet became popular, viruses tended to be transferred by disk. Nowadays, the people who create viruses have found a much easier and wider audience for their viruses via the Internet. This is where ninety-nine percent of viruses are spread, either by email attachments or embedded in software.

How do I know if my computer has a virus?

Viruses can cause your computer to do practically anything. It is hard to be certain that a problem is due to a virus, unless it causes a message to scroll across your screen saying ‘I am a virus’! However, there are some tell-tale signs that a virus may be behind the problems that you are having with your computer.

Examples are:

• sudden loss of files;
• the computer shutting itself down after certain tasks;
• the computer starting to run much more slowly than normal (also see SpyWare).

Absolutely anything out of the ordinary that starts happening on a regular basis may be caused by a virus.

Anti-virus software

As we have said before, prevention is always better than a cure. Keeping free of viruses is preferable to having to treat them! Anti-virus software has been designed to seek out and destroy viruses already on, or trying to attack, your machine, before they have the chance to do any damage.

There are various companies that produce anti-virus software. Most programs can be purchased from any shop that sells computer software, although there is also free anti-virus software available as a download from the Internet.

The most popular titles for purchase are Norton Anti Virus and Macafee Anti Virus. One of the most popular free anti-virus software titles is AVG.

Anti-virus software has two main parts to it. One is the program itself, which gives your computer the power to scan files to check for viruses. The other part lists the virus definitions. Virus definitions are basically a large collection (or database) of information on past and current viruses. Without the virus definitions, your anti-virus software wouldn't know what it was looking for.

For every new virus that is found, a cure or definition needs to be written to help combat it, so it is very important to keep the virus definitions up to date. This is done by downloading any updates from the Internet, which is usually done automatically by the anti-virus software as soon as you connect to the Internet.

Tips on helping to prevent your computer from becoming infected with viruses

• Don’t open any files or software that has been attached to an email unless you trust the sender, and are expecting them to send you something. Even if you trust the sender, the attachment may have become infected with a virus without their knowledge. There are viruses that make your computer send emails, with infected files attached, to everyone in your address book. These emails and their attached files can look genuine, but can cause havoc.
• Run anti-virus software on your computer, and make sure it is updated (the virus definitions) at regular intervals.
• Be careful when installing freeware and shareware (see SpyWare for definitions).