The ILOVEYOU worm infects millions of computers worldwide in a few hours.
Distributed denial-of-service (DDoS) attacks knock Amazon.com, Yahoo and eBay offline. The attacks occur when hackers co-opt University of California, Santa Barbara, computers to flood the target sites with traffic.
The Klez worm sends copies of itself to all of the e-mail addresses in its victims' directories. It overwrites files and creates hidden copies of the originals. It's huge in scope but the monetary damage it causes is small.
The Slammer worm infects hundreds of thousands of computers worldwide in less than three hours.
A Russsian hacker group known as the Hang-Up Team builds a Web site featuring administrative tools for attacking U.S. financial institutions.
North Korea claims to have trained 500 hackers to crack computer systems in South Korea and Japan and their allies.
The U.S. Secret Service seizes control of the Shadowcrew Web site and arrests 28 people in eight states and six countries. Allegations include conspiracy to defraud the U.S. and exposing confidential Secret Service documents.
The My Doom worm uses psychological tricks to persuade recipients to open attachments containing a virus.
Estonia suffers a massive DDoS attack that knocks out government and banking networks.
A spear-phishing incident at the Office of the Secretary of Defense compromises sensitive U.S. defense information.
A 10-month cyberespionage investigation of the GhostNet finds that 1,295 computers in 103 countries have been spied on, with circumstantial evidence pointing to China. GhostNet uses a malicious software program called gh0st RAT (remote-access tool) to steal sensitive documents and control webcams in infected computers.
Hackers break into Defense Department computers and download terabytes of data containing design information about the Joint Strike Fighter project, a $300 billion initiative to develop a stealth fighter plane.