A German teenager created some of the most harmful worms to hit computers around the world during the first half of 2004, according to experts.
Despair is how most people react once their computer has been hit
Sven Jaschan, a student from a small town in the German state of Lower Saxony, made headlines earlier this year after admitting that he created the NetSky and Sasser worms that infected millions of computers around the globe.
He was responsible for 70 percent of all worms that traveled through cyberspace in the first half of 2004.
"It's staggering that a single German teenager can have such a dramatic influence," Graham Cluley of Sophos, a company specializing in anti-virus programs, told reporters.
Personal computer with virus alert on the screen
Altogether, Sophos experts registered 4,677 new viruses (which reproduce using a host program), worms (which reproduce without a host program) and so-called Trojans (which secretly execute other changes to computer programs) since January.
All of these attack programs have short shelf lives and disappear almost as quickly as they emerge.
Jaschan used security gaps in Microsoft's operating programs Windows XP and Windows 2000 to spread his programs. Sasser traveled directly from computer to computer and not -- as usual -- via e-mail attachment; A simple Internet connection was sufficient to infect unprotected computers. After an attack, the worm immediately started 128 consecutive attacks via the Internet or within a local network.
But Jaschan's original intention had been to create a "good" worm that would hunt "bad" worms throughout the Internet. His goal was to disarm worms such as MyDoom and Bagle, which were making their damaging way through the Web at the time. Jaschan sent NetSky and Sasser to infect computers and start "cleaning up" infections from previous worms.
The self-proclaimed Internet policeman apparently lacked the programming knowledge to prevent harm to computers. Sasser shut down infected systems and restarted them. Jaschan said he had not planned this, but couldn't solve the problem.
"Sasser was meant to be a warning shot," Jaschan said, adding that he wasn't a criminal programmer, but rather intended to alert the public to security holes that had to be fixed by Microsoft.
It's still unclear how much damage Sasser caused -- so far, 30 to 40 claims have been submitted, according to Jaschan's defense attorney. They range from €45 ($55.5) to €3,500.
Suits against Jaschan are not likely to reach exorbitant proportions. But that's probably not going to influence the computer sabotage criminal case that's currently pending.