By: HISTORY.com Editors
Mydoom—the fastest-spreading email worm ever—is discovered
On January 26, 2004, security experts detect an email worm called "Mydoom," which quickly becomes the fastest-spreading of its kind. Within two days, the British security firm MessageLabs identifies more than 1.8 million copies of the virus circulating in 168 countries.
Computer viruses date back to 1971, when engineer Bob Thomas created the “Creeper,” a self-replicating worm that displayed the message, “I’m the creeper: catch me if you can.” Designed as an experiment, the Creeper did not harm the computers it infected. Many viruses that followed, however, were deliberately malicious.
The Birth of the Internet
Show: HISTORY Honors 250On October 29, 1969, Stanford programmer Bill Duvall sent a single-word message—"login"—to UCLA student programmer Charley Kline, 350 miles away. Transmitted between two computers that each filled an entire room, this message marked the first communication between networked computers and is widely regarded as the birth of the internet.
Mydoom was one of them. The worm allowed hackers to access infected email accounts and send spam, spreading further whenever users opened infected email attachments. On February 1, 2004, Mydoom flooded the website of the software company SCO Group with requests, causing it to crash. SCO Group and Microsoft each offered a $250,000 reward for information leading to Mydoom’s anonymous creator.
Craig Schmugar, a researcher at the computer security company McAfee, was among the first to analyze Mydoom. He coined its name after noticing the word “mydom”—short for “my domain”—in the virus’s code.
“It was evident early on that this would be very big,” Schmugar told Newsweek. “I thought having ‘doom’ in the name would be appropriate.”
After a precipitous rise, Mydoom’s circulation began to decline in early February 2004. Yet the worm never fully disappeared. Variants of Mydoom were still detected as late as 2019, persisting as long as users continue to click on the infected email attachments it generates.
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Citation Information
- Article Title
- Mydoom—the fastest-spreading email worm ever—is discovered
- Author
- HISTORY.com Editors
- Website Name
- History
- Date Accessed
- November 04, 2026
- Publisher
- A&E Television Networks
- Last Updated
- January 23, 2026
- Original Published Date
- January 23, 2026
