A German man (18) who confessed to creating the "Sasser" computer worm apparently released a new version of the program shortly before he was arrested last week, investigators said today.
The teenager was arrested on Friday in the northern town of Waffensen after informants seeking a reward tipped off Microsoft. In a search of his family's home, German investigators confiscated his customised computer, which contained the worm's source code.
Today, German investigators said Microsoft had reported some computer users were having problems with "Sasser e," a variation of the original worm.
A spokesman for the state criminal office in Hanover said the worm was "a slightly modified form" of the program that raced around the world over the past week, exploiting a flaw in Microsoft's Windows operating system. The suspect likely programmed it "immediately before his discovery," he said.
Four versions of Sasser were already known. Police have said the German teenager, whose name was not released, was responsible for all of them in addition to the "Netsky" virus.
The student is being investigated on suspicion of computer sabotage, which carries a maximum sentence of five years in prison. He was released pending charges after questioning last Friday, where he admitted creating Sasser, police said.
Investigators are still evaluating material from the confiscated computer.
The teenager has told officials that his original intention was to create a virus, "Netsky A," that would combat the "Mydoom" and "Bagle" viruses, removing them from infected computers. During that effort, he developed the Netsky virus further and after modifying it created Sasser.