Due to an editing error, the initial version of this timeline incorrectly stated who was responsible for the Solar Sunrise attacks. While the hacking group L0pht was in the news at the time discussing those attacks, it did not design or implement those attacks.
1964
AT&T begins crackdown on "phreakers," who use tone generators to make free phone calls. By 1970, it has achieved 200 convictions.
1978
Engineers at Xerox Palo Alto Research Center design a computer worm, a short program that searches a network for underused processors. Though built to improve computer efficiency, it is the genesis of the destructive, modern worm.
1983
The FBI busts young hackers known as the 414s, who use an Apple II+ and a modem to break into 60 computer systems, including one at Los Alamos National Laboratory.
1986
"The Brain," one of the first PC viruses, is released in Pakistan.
1994
30-year-old Russian Vladimir Levin leads a group of hackers who break into Citibank's systems and steal millions of dollars. Levin is later sentenced to three years in prison.
1996
Hackers alter Web sites of the U.S. Department of Justice in August, the CIA in October and the U.S. Air Force in December. The GAO reports that hackers attempted to break into Defense Department computer files 250,000 times in 1995 alone. About 65% of the attempts were successful, according to the report.
1998
The Solar Sunrise attacks exploit well-known vulnerabilities in Sun's Solaris operating system to implant sniffer programs in more than 500 military, government and private-sector computer systems. Investigators originally suspect operatives in Iraq, but later learn that two California teenagers were responsible.