Two British men have been found guilty of releasing the T-K worm and have been sentenced to a total of nine months in prison.
Andrew Harvey, 24, of Sherburn Village, Co Durham, was jailed for three months, and Jordan Bradley, 22, of Darlington, was jailed for six months.
Appearing at Newcastle Crown Court both admitted conspiracy to cause unauthorised modification of computers with intent.
"With any luck these prison sentences will send a stern message to the virus community that distributing malicious code is not acceptable," said Alan Bentley, UK managing director of patch management company PatchLink.
"This hacking group, THr34t-Krew, used the virus to scan computers for vulnerabilities to start distributed denial of service attacks on other computers and websites. This type of activity can only be viewed as malicious and needs to be addressed."
Harvey and Bradley were arrested two years ago for releasing the worm between 1 January 2002 and 6 February 2003. They were picked up after a joint operation between the FBI and the UK's National High Tech Crime Unit.
"These jail sentences are a reminder of how much the game has changed since they were arrested in 2003," said Pete Simpson, ThreatLab manager at e-security firm Clearswift.
"These are typical bedroom hackers looking for notoriety and column inches. Two years down the line, such attacks are much more targeted and led by organised crime. Their motivation is one thing only: money."
See also:
All Hacking