Computer Virus History

Cloner Elk is credited with being the first computer virus to appear "in the wild" -- outside the single computer or lab where it was maded. Written in 1982 by Rich Skrenta, it attached itself to the Apple DOS 3.3 OS and spread by floppy disk. The first computer virus was a boot sector virus called (c)Brain, created in 1986 by two brothers, Basit and Amjad Farooq Alvi from Pakistan. They reportedly created the virus to deter pirated copies of software they had written. Before computer LAN became widespread, most "worms" spread on removable media, particularly FD. In the early days of the personal machine, many users regularly exchanged information and programs on floppies. Some viruses spread by infecting software stored on these disks, while others installed themselves into the disk boot sector. Traditional computer viruses emerged in the 1980s, driven by the spread of PC and the resultant increase in BBS and modem use, and software sharing. Bulletin board driven software sharing contributed directly to the spread of Trojan horse programs, and viruses were written to infect popularly traded software. Shareware and bootleg software were equally common vectors for viruses on BBS's. Since the mid-1990s, macro viruses have become common. Most of these "code" are written in the scripting languages for Microsoft software such as Word and Excel. These viruses spread in Microsoft Office by infecting documents and spreadsheets. Since Word and Excel were also available for Mac OS, most of these viruses were able to spread on Macintosh computers as well. A computer virus may also be transmitted through IM(instant messaging). A virus may send a web address link as an instant message to all the contacts on an infected machine. If the recipient, thinking the link is from a friend and follows the link to the website, the virus hosted at the site may be able to infect this newest computer and continue propagating. The new species of the virus family is the cross-site scripting virus. The virus emerged from research and was academically demonstrated in 2005. This virus utilizes cross-site scripting vulnerabilities to propagate. Since than there have been multiple instances of the cross-site scripting viruses in the wild, most notable sites affected have been Google and Yahoo.