ប្រវត្តិនៃ VIRUSES

In 1949 Hungarian American mathematician John von Neumann, at the Institute for Advanced Study in Princeton, New Jersey, proposed that it was theoretically possible for a computer program to replicate. This theory was tested in the 1950s at Bell Laboratories when a game called Core Wars was developed, in which players created tiny computer programs that attacked, erased, and tried to propagate on an opponent's system.

In 1983 American electrical engineer Fred Cohen, at the time a graduate student, coined the term virus to describe a self-replicating computer program. In 1985 the first Trojan horses appeared, posing as a graphics-enhancing program called EGABTR and as a game called NUKE-LA. A host of increasingly complex viruses followed.

The so-called Brain virus appeared in 1986 and spread worldwide by 1987. In 1988 two new viruses appeared: Stone, the first bootstrap-sector virus, and the Internet worm, which crossed the United States overnight via computer network. The Dark Avenger virus, the first fast infector, appeared in 1989, followed by the first polymorphic virus in 1990.

Computer viruses grew more sophisticated in the 1990s. In 1995 the first macro language virus, WinWord Concept, was created. In 1999 the Melissa macro virus, spread by e-mail, disabled e-mail servers around the world for several hours, and in some cases several days. Regarded by some as the most prolific virus ever, Melissa cost corporations millions of dollars due to computer downtime and lost productivity.

The VBS_LOVELETTER script virus, also known as the Love Bug and the ILOVEYOU virus, unseated Melissa as the world's most prevalent and costly virus when it struck in May 2000. By the time the outbreak was finally brought under control, losses were estimated at U.S.$10 billion, and the Love Bug is said to have infected 1 in every 5 PCs worldwide.

The year 2003 was a particularly bad year for computer viruses and worms. First, the Blaster worm infected more than 10 million machines worldwide by exploiting a flaw in Microsoft’s Windows operating system. A machine that lacked the appropriate patch could be infected simply by connecting to the Internet. Then, the SoBig worm infected millions more machines in an attempt to convert systems into networking relays capable of sending massive amounts of junk e-mail known as spam. SoBig spread via e-mail, and before the outbreak was 24 hours old, MessageLabs, a popular e-mail filtering company, captured more than a million SoBig messages and called it the fastest-spreading virus in history. In January 2004, however, the MyDoom virus set a new record, spreading even faster than SoBig, and, by most accounts, causing even more damage.