A German teenager who confessed to creating the Sasser computer worm has been found guilty of three counts of computer sabotage and four counts of data manipulation, and given a suspended sentence of 21 months.

Sven Jaschan, 19, was sentenced today at the district court in Verden, Germany, according to a statement from the court.

Jaschan will be released on three years' probation. If he commits another crime during the probation period, he will be jailed at a juvenile detention centre to serve the 21-month sentence.

In addition, Jaschan must perform 30 hours of community service in a home for the elderly or a hospital.

At the time of his arrest in May 2004, Jaschan had confessed to creating the Sasser worm. He was arrested at the family's home in Waffensen, Germany, after Microsoft received a tip from an informant seeking a reward from the software company.

Sasser crashed hundreds thousands of computers around the world last year by exploiting a flaw in a Windows software component called the Local Security Authority Subsystem Service, or LSASS. The worm scanned the internet in search of vulnerable computers.

On April 13, Microsoft had released a software patch, MS04-011, which plugs the LSASS hole, but many companies and individuals had not installed it in time to prevent the Sasser worm from affecting their systems.