What are Computer Viruses?



Computer viruses are actually small software programmes written with malicious intent. They are tailor-made to spread automatically from one computer to another through a variety of means. Once they reach a computer, they immediately create many versions of themselves and infect a lot of files.

Viruses are written by people who are either software engineers or know programming languages. Often, these are young teenagers still studying computer science in colleges who are just doing it for fun or trying to impress their friends with their intellect and competence.

How do Viruses Spread?

Not very long ago, floppy disk was the only way we could transfer data files from one computer to another. Therefore, this was the only media available to viruses for travelling in cyber-space. Now, digital media used for transferring files has multiplied. Apart from floppy disks – which are now almost obsolete – there are optical disks (including compact disks and digital video disks) as well as USB Flash drives used for transferring data. Apart from these, emails are the main carriers of digital files today over long distances.

In the modern world, the Internet has been a great boon. It is an international network made up of old-fashioned copper wires, fibre-optic cables as well as micro-wave and satellite links that connects almost all computers of the world. We can use it to browse millions of Websites, download useful information as well as send emails and pictures to friends, relatives and business contacts far and wide.

Internet has also emerged as the ideal vehicle that viruses use to spread themselves worldwide in a matter of days. Indeed, today most viruses are introduced to your computer through the Internet. Emails are the main culprit. What happens is that a virus residing in your computer automatically accesses your email address book, attaches itself to emails and starts sending them to everyone in your email database without your getting to know about it.

When the recipients see your email, they click on it and their computer becomes infected with the virus too. The latter then plays out the same game with the new computer and sends itself to every address in its email list. This is like a chain reaction whose shock-wave encompasses millions of computers.

Apart from email, viruses can enter your computer when you browse websites. The latter may have some hidden viruses and other troublesome software such as spyware. When you click on a link, a virus may get activated and download itself onto your computer hard disk.

Trojans are a version of computer viruses. Like the proverbial Trojan horse, these hide themselves inside harmless-looking files such as digital pictures, greeting cards, video clips and audio files. When you download any of these onto your computer, the hidden virus comes alive and starts infecting your hard disk.

Viruses can damage your computer in different ways. Some of these are just nuisance-creators, like, for example, a virus forcing you to press a particular keyboard button every five minutes if you want to continue working. But many are deadly in their effect and try to wipe your hard disk clean of all data.

Anti-Virus Vaccine

Every year, viruses are responsible for massive damage in terms of lost data and the money spent by individuals and businesses in trying to recover that data. Companies suffer immense financial setbacks if they are unable to recover their critical files. That is why most countries in the world have laws that mandate strict punishments for anyone found responsible for creating computer viruses and injecting them into cyber-space.

In the last few decades, an entire new industry has cropped up that specialises in anti-virus software products. Called virus vaccines, these are meant to be loaded onto your hard disk. Whenever you boot up your computer, this software gets activated and keeps an eye on your files. It does not allow you to download any file or open any website link before it has first vetted it to see if it is not hiding a dangerous virus. This makes your computer quite safe.

Also, the anti-virus software periodically scans your entire hard drive to check for viruses. Newer viruses are getting created every day. Therefore, the anti-virus software keeps downloading newer virus definitions from its company website so that your computer protection remains up to date.