What is a virus and where do they come from?

Nearly everyone who owns a computer has not only heard of but also fears the computer virus.

Nearly everyone who owns a computer has not only heard of but also fears the computer virus. The recent Conficker virus has made world news, infecting over 15 million computers globally and spurring Microsoft to offer a quarter of a million dollars reward for the virus creator's prosecution. This latest virus outbreak has reminded us all how vulnerable our personal information can be online, but what are computer viruses and where do they come from?

What is a Virus?

A computer virus is any program that can copy itself and infect a computer much like a regular virus can spread from person to person.

Viruses replicate in order to gain control of computer systems, corrupt computer programs, data files and other computers. These malicious programs are often very small in size (between 1kb-1mb), enabling them to run on a computer without the user ever being aware of its presence.

Once installed, a virus can spread itself through several methods. It can email itself as an attachment, infecting every sent email or it can silently generate emails to everyone in your address book. Viruses can also infect USB drives, CD's and floppy disks, thereby spreading from one computer to another via the user. Even more alarmingly, some viruses can simply use an infected machine as a launch point and spread to all computers connected to a network without any user intervention at all.

How are Viruses Made?

Richard Skrenta, the man credited with creating the very first computer virus in 1982, had no idea that his simple high school prank could one day cause so much destruction. Viruses have evolved into instruments that not only destroy computer systems and networks, but also steal user identities and banking information.

All computer viruses are created by rogue programmers, often referred to as hackers, but their motivations vary greatly.

Some create viruses as revenge for perceived injustices. These hackers are normally disgruntled employees or people who believe 'the system' has failed them in some way. They may write a virus to destroy company computers and networks or target government agencies. Though these viruses can cause a great amount of damage, they are normally isolated to specific targets.

Adolescent hackers still make up a significant number of virus creators. Many create viruses just to see 'what will happen' and others create these electronic menaces in hopes of making the news. The motivation of these teenage hackers is to prove their programming ability, gain recognition from their peers and, ultimately, the rest of world.

However there are a growing number of virus writers who work for syndicated crime rings and their software has a much more define purpose. Syndicated hackers create viruses in order to gain access to remote computers. These programs are used to copy personal information such as banking details, home addresses, names and government identity numbers. The stolen data is often sold on for use in identity fraud, spamming and to generate website traffic for profit. These programmers have plenty of motivation. Identity theft in the US alone reached nearly $56.6 billion during 2006.