1978 - Xerox PARC Virus, the first "In House" Virus at Xerox's Palo Alto Research Center

John Shoch, inventor of this new form of programming, created the dynamic, roaming program known as the "worm". One night the program became corrupted so badly it crashed its host computer. Sensing it had lost a segment, the control worm sent out a tendril to another idle Alto. That host crashed, and the next, and the next. For hours, the silent carnage spread through the building until scores of machines were disabled

1981 - The First Virus In The Wild

It was spread on Apple II floppy disks (which contained the operating system) and reputed to have spread from Texas A&M. It displayed a little rhyme on the screen:     

It will get on all your disks
It will infiltrate your chips
Yes it's Cloner!
It will stick to you like glue
It will modify ram too
Send in the Cloner!

1983 - The First Documented Experimental Virus

On November 10, a virus loaded on VAX 11/750 system running Unix was demonstrated

1986 - Brain, PC-Write Trojan, & Virdem

Two brothers from Pakistan analyzed the boot sector of a floppy disk and developed a method of infecting it with a virus dubbed "Brain" It spread widely on the popular MS-DOS PC system

1987 - File Infectors, Lehigh, & Christmas Worm

A fast-spreading (500,000 replications per hour) worm also hit IBM mainframes during this year: the IBM Christmas Worm.

1988 - MacMag, Scores, & Internet Worbm

MacMag , a Hypercard stack virus on the Macintosh is considered the first Macintosh virus and the Scores virus was the source of the first major Macintosh outbreak. The Internet Worm (Robert Morris' creation) causes the first Internet crisis and shut down many computers.

1989 - AIDS Trojan

This Trojan is famous for holding data hostage. The Trojan was sent out under the guise of an AIDS information program . When run it encrypted the user's hard drive and demanded payment for the decryption key.

1990 - VX BBS & Little Black Book (AT&T Attack)

The first virus exchange (VX) BBS went online in Bulgaria. Here virus authors could trade code and exchange ideas.

1991 - Tequila

Tequila was the first polymorphic virus; it came out of Switzerland and changed itself in an attempt to avoid detection.

1992 - Michelangelo, DAME

Michelangelo was the first media darling. A wordwide alert went out with claims of massive damage predicted. The same year the Dark Avenger Mutation Engine (DAME) became the first toolkit that could be used to turn any virus into a polymorphic virus.

1992 - VCL

Also that year the Virus Creation Laboratory (VCL) became the first actual virus creation kit. It had pull-down menus and selectable payloads.

1995 - Year of the Hacker

Hackers attacked Griffith Air Force Base, the Korean Atomic Research Institute, NASA, Goddard Space Flight Center, and the Jet Propulsion Laboratory. GE, IBM, Pipeline and other companies were all hit by the "Internet Liberation Front" on Thanksgiving.

1995 - Concept

The first macro virus to attack Word, Concept, is developed.

1996 - Boza, Laroux, & Staog

Boza is the first virus designed specifically for Windows 95 files . Laroux is the first Excel macro virus. And, Staog is the first Linux virus (written by the same group that wrote Boza).

1998 - Strange Brew & Back Orifice

Strange Brew is the first Java virus. Back Orifice is the first Trojan designed to be a remote administration tool that allows others to take over a remote computer via the Internet. Access macro viruses start to appear.

1999 - Melissa, Corner, Tristate, & Bubbleboy

Melissa is the first combination Word macro virus and worm to use the Outlook and Outlook Express address book to send itself to others via E-mail. Tristate is the first multi-program macro virus; it infects Word, Excel, and PowerPoint files. Bubbleboy is the first worm that would activate when a user simply opened and E-mail message in Microsoft Outlook

2000 - DDoS, Love Letter, Timofonica, Liberty (Palm), Streams, & Pirus

The first major distributed denial of service attacks shut down major sites such as Yahoo!, Amazon.com, and others. In May the Love Letter worm became the fastest-spreading worm (to that time); shutting down E-mail systems around the world. June 2000 saw the first attack against a telephone system.

2001 - Gnuman, Winux Windows/Linux Virus, LogoLogic-A Worm, AplS/Simpsons Worm, PeachyPDF-A, Nimda

The Nimda worm demonstrated significant flexibility in its ability to spread and used several firsts. While not new in concept, a couple of worms created a fair amount of havoc during the year: Sircam (July), CodeRed (July & August), and BadTrans (November & December).

2002 - LFM-926, Donut, Sharp-A, SQLSpider, Benjamin, Perrun, Scalper

Early in January LFM-926 showed up as the first virus to infect Shockwave. Also in early January Donut showed up as the first worm directed at .NET services. In March, the first native .NET worm written in C#, Sharp-A was announced.

2003 - Slammer, Sobig, Lovgate, Fizzer, Blaster/Welchia/Mimail

Sobig, a worm that carried its own SMTP mail program and used Windows network shares to spread started the year. Sobig variants continued to multiply throughout the year. Slammer, exploiting vulnerabilities in Microsoft's SQL 2000 servers, hit Super Bowl weekend.. Starting in early May Fizzer spread via usual E-mail methods but also used the KaZaa peer-to-peer network to spread. August is (in)famous for a combination of Sobig.F, Blaster (also known as Lovsan and MSBlast), Welchia (or Nachi), and Mimail; all spreading rapidly through a security vulnerability in a Windows Distributed Component Object Model (DCOM)

2004 - Trojan.Xombe, Randex, Bizex, Witty, MP3Concept, Sasser, Mac OS X, W64.Rugrat.3344

Year 2004 started where 2003 left off with social engineering taking the lead in propagation techniques. There were more attacks in the first 3 months of 2004 than all of 2003!