The window of the home of the Sasser worm creator with Homer Simpson of the comic strip The Simpsons on it. (AFP)

Hanover, May 8 (Reuters): German police have arrested an 18-year-old man suspected of creating the “Sasser” computer worm, believed to be one of the Internet’s most costly outbreaks of sabotage.

Spokesperson Frank Federau for Lower Saxony police said the man was arrested yesterday. He said the suspect admitted to programming the worm but authorities did not know if he had created all the versions of it.

Software giant Microsoft had received anonymous tip-offs about the worm’s creator and then contacted the Federal Bureau of Investigation and German police, Federau said. All three worked together to find the suspect. It was the lure of cash that proved the man’s undoing. A group of individuals from Lower Saxony approached Microsoft on Wednesday inquiring about reward money should they turn in the man. The US software giant in the past has put bounties of up to $250,000 on the heads of other notorious virus writers.

Microsoft general consul Brad Smith said the company agreed to pay the informants if there is a conviction. “They did not stumble upon him through technical analysis. They were aware of who he was,” Smith said, declining to elaborate on their relationship to the suspect and saying only the number of informants was less than five.

Surprised at the rapid developments, security experts said this could be the single biggest arrest yet in bringing down a virus-writing gang. Federau said the man, who lived with his parents near the central German town of Rotenburg, did not have any links with organised crime. But he could not confirm if the suspect had ties to other worm programmers.

All the teenager’s computers were confiscated by police but the suspect himself was not in custody, Federau said.

Sasser, a tenacious computer worm, is expected to infect millions of machines before it runs its course. Since appearing a week ago, it has wreaked havoc on personal computers running on the ubiquitous Microsoft Windows 2000, NT and XP operating systems.

Separately, police in Baden-Wuerttemberg said they had arrested a 21 year-old man who confessed to programming the Internet worm “Agobot” which was later renamed as “Phatbot”. However, the arrests were not connected.