Sven Jaschen was just 17 when he released Sasser, in April 2004. The original worm and its variants infected countless thousands of Windows-based PCs worldwide -- in May 2004, it represented more than half of all worms detected.
Sasser also disrupted several important computer networks, including that of the UK's coastal service, which reportedly failed to patch against the virus.
Jaschen, who is also suspected of creating the Netsky virus, will be sentenced later this week.
Despite the damage caused by Jaschen's malware, Graham Cluley, senior technology consultant at Sophos, hopes that the teenager isn't sent to prison.
"I'm not sure what the point of jailing him would be," Cluley said, in an interview last week, adding that unlike today's serious cybercriminals Jaschen hadn't stolen credit cards or broken into a bank.
"They should give him community service and a big fine," Cluley added.
ZDNet UK's Graeme Wearden reported from London. For more coverage from ZDNet UK, click here.
I am sorry but these hackers affect peoples lives and should be punished by long jail terms.