Updated An 18-year-old German student has admitted writing the infamous Sasser worm, following his arrest by local police on Friday.
The man (since named as Sven Jaschan) from the village of Waffensen, between Bremen and Hamburg, in the northern German state of Lower Saxony is also suspected of releasing all 28 versions of the equally notorious NetSky worm. The investigation which led to his arrest came from a tip-off to Microsoft from unspecified individuals who stand to collect a payout of up to $250,000 under the company's $5m anti-virus reward program. German papers report that Jaschan's own classmates turned him in but this remains unconfirmed.
Technical experts from Microsoft were able to verify the information received and German police, helped by investigative support from the FBI, launched an operation which led to a raid on the Jaschan's home - less than a week after Sasser began infecting hundreds of thousands of computers worldwide. Investigators seized computers and disks from his home, which he shares with his parents. His mother, Veronika, and stepfather run a small PC Help business prompting speculation their son may have written the worm in a misguided attempt to drum up business. Jaschan Junior has been released on bail after questioning by police and pending further investigations.
Frank Federau, a spokesman for German police in Lower Saxony, told Reuters: "We are absolutely certain that this really is the creator of the Internet worm because Microsoft experts were involved in the inquiry and confirmed our suspicions and because the suspect admitted to it".
Police reckon the accused created all four variants of Sasser. The alleged perp faces charges punishable by up to five years in prison if convicted in an adult court. Since he only turned 18 on April 29 he may end up getting tried in a juvenile court, where a much lighter sentence might apply.
Jaschan reportedly told police his ultimate goal with NetSky was to develop an anti-virus 'virus', which could automatically remove MyDoom and Bagle. He was encouraged by his class mates - who knew he was working on these programs - to develop the even more aggressive Sasser worm, according to German paper Süddeutsche Zeitung.
Sasser targets a recently announced vulnerability in Windows causing vulnerable machines to shutdown and reboot. The worm has caused widespread disruption affecting the operations of companies ranging from Finnish bank Sampo and Germany's Deutsche Post to the UK Coastguard. Advice on how to deal with infected or vulnerable machines can be found here.
In a parallel move, police in the southern German state of Baden-Wuerttemberg have arrested a 21-year-old man on suspicion of creating the Agobot and Phatbot Trojans.
Investigators are refusing to speculate about links between the two virus writers or alleged connections to larger VX (virus-writing) groups, pointing out that both investigations are at an early stage. ®
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