Virus strikes the Internet - Virus Ithihaas

LONDON (Reuters) - The MyDoom Internet worm claimed its first scalp on Sunday, paralysing the Web site of American software firm SCO Group with a massive data blitz.

SCO is not alone. Microsoft Corp has been targeted by a second variant of MyDoom, dubbed MyDoom.B. That attack is timed to kickoff on Tuesday.

MyDoom, the latest worm to infect computers over the Internet, is the fastest-spreading attack since last summer's twin attacks by the Blaster worm and SoBig virus, computer security experts said.

Following are brief descriptions of some of the major viruses, according to various security firms including TruSecure/ICSA Labs, Trend Micro, F-Secure Corp., Sophos, Network Associates Inc., and Symantec Corp.

-- In 1986, two brothers, Amjad and Basit Farooq Alvi, wrote what is thought to be the first PC virus to infect floppy disks. Dubbed the "Pakistani Brain" virus, it was designed to advertise their software company, Brain Computer Services in Lahore, Pakistan.

-- The first worm -- a virus that spreads through the Internet -- was released on November 2, 1988 by Cornell graduate student Robert Morris Jr. The "Morris Worm" exploited a flaw in the Unix operating system and spread within days to about 6,000 mainframes, or between five and 10 percent of the total on the Internet at the time. Morris, the son of a computer security expert at the U.S. National Security Agency, was convicted of violating the Computer Fraud and Abuse Act.

-- In 1989, a teenager in Sofia, Bulgaria, released the Dark Avenger virus that destroyed data and contained references to lyrics from metal rock band Iron Maiden, including "Eddy lives ... somewhere in time." He also wrote the first polymorphic virus, which changes characteristics to avoid detection.

-- Ching Ing-hau, a sergeant in the Taiwanese army, wrote the Chernobyl virus, also called CIH, in 1998. Set to activate on the anniversary of the Chernobyl nuclear disaster, April 26, it would try to erase the hard drive on an infected computer. Experts said he wrote it to get revenge on the anti-virus industry after the army got infected by a virus.

-- In 1999 David Smith of New Jersey wrote the Melissa virus that spread via e-mail and infected Microsoft Word documents. Smith had two aliases, "Vicodin" for his virus writing, and "Doug Winterspoon" for when he was posing as a legitimate virus expert, experts said. Smith did not go to prison for several years but is now serving time.

-- Filipino university student Onel de Guzman released the "IloveYou" or "LoveLetter" e-mail virus in 2000. It tricked people into opening an infected e-mail attachment and installed a keystroke logger so he could get access to passwords on infected machines.

-- Jan De Wit, from The Netherlands, wrote the Anna Kournikova virus in 2001 using the alias "On the Fly". Created with virus generation software, the worm tricked e-mail users into clicking on an attachment that purported to be a picture of Russian tennis star Kournikova. He was charged with spreading data via a computer network with the intent to cause damage.

-- Blaster worm and the Sobig e-mail virus disabled computers and snarled Internet traffic across the globe in August and September 2003. Sobig.F became one of the most widespread viruses ever, crippling corporate e-mail networks and filling home users' inboxes with a glut of messages before jetting copies off exponentially to more victims. The "Blaster", or "LovSan" worm spread through a security hole in Windows.

-- MyDoom - also known as Novarg or Shimgapi has spread rapidly, mostly in North America, accounting for one in nine messages globally. The volume of messages clogged networks and appeared to be concentrated in corporate environments. Later MyDoom.B, a new variant emerged to target Microsoft Corp.'s Web site, security experts said.