Teenager admits creating Sasser computer worm

A German teenager confessed to creating last year’s Sasser worm as he went on trial today on charges including computer sabotage.

The trial of Sven Jaschan, 19, was being held behind closed doors in the north-western town of Verden because he was a minor at the time of the offence. He entered the courthouse through a side door and did not speak to reporters.

After proceedings began, Jaschan “admitted to the alleged offences in every detail,” said court spokeswoman Katharina Kruetzfeld. Authorities said Jaschan already confessed to creating the worm at the time of his arrest in May 2004.

The charges, which also include disrupting public services and illegally altering data, carry a maximum sentence of five years in prison. However, Kruetzfeld said that, as a minor, he faces a lesser penalty.

Jaschan was arrested at his family’s home after Microsoft received a tip from an informant seeking a reward. The worm had raced around the world, exploiting a flaw in the company’s Windows 2000 and Windows XP operating systems.

Sasser caused infected computers to crash and reboot, making it impossible to work on them. The worm snarled tens of thousands of computers and caused Internet traffic to slow.

Authorities who questioned Jaschan said they got the impression his motive was to gain fame as a programmer. He was arrested sitting at his computer at the house of his mother, who runs a computer store in the small northern town of Waffensen.

The teenager has told officials his original intention was to create a virus, Netsky A, that would combat the Mydoom and Bagle viruses, removing them from infected computers. That led him to develop the Netsky virus further – and to modify it to create Sasser.

Investigators say he had launched a new version of Sasser that was meant to limit the damage just before his arrest.

In their indictment, prosecutors chose the cases of three German city governments and a public broadcaster whose systems were disrupted.

Five suspected accomplices – including the informant – were also under investigation, but Jaschan “is the big fish,” prosecutor Helmut Trentmann said before the trial.

The trial was due t last three days, with a possible verdict on Thursday. Because defendants do not enter formal pleas under German law, proceedings continue despite Jaschan’s confession.