Federal law-enforcement officials said that Jeffrey Lee Parson, of Hopkins, Minn., who was arrested Friday, is alleged to have altered malicious computer code in the "Blaster" worm, which targeted Microsoft software.
According to federal officials, he then rereleased it, infecting 7,000 computers -- a fraction of the more than one million infected by the Blaster worm, whose creator is still at large, the Wall Street Journal reported.
"The author of Blaster and (Blaster variant) Nachi did an order of magnitude of harm greater than Parson did," said David Kennedy, director of research services at Trusecure, a computer-security consulting company in Herndon, Va.
"Catching them would be the far greater prize for law enforcement and a greater deterrent."
The U.S. attorney in Seattle, John McKay, told the Journal he is confident that there will be further arrests.