The author of the original Blaster worm may never be caught, but the writer of one of its subsequent variants has just been sentenced to a lenient 18 months behind bars for his crime.

Jeffrey Lee Parson, who also received a 3-year supervision order, was responsible for the W32/Blaster-B worm that infected a reported 48,000 computers when it spread round the Internet in August 2003, causing damage estimated at $1.2 million. He still faces a bill for the trouble he has caused, which will be set at a hearing on 10 February.

Blaster-B’s primary effect was to allow its writer backdoor access to infected systems, but it will go down in history for its secondary payload - launching a heavyweight denial-of-service attack on Microsoft’s website. It was this attack that accounted for the worm’s economic impact as Microsoft spent over a million dollars cleaning up the problems it caused.

The Internet "has created a dark hole, a dungeon if you will, for people who have mental illnesses or people who are lonely," the presiding judge was reported as saying of the 19 year-old defendant. "I didn't see any parent standing there saying, 'It's not a healthy thing to lock yourself in a room and create your own reality," she concluded.

In many ways, Parson fits the stereotype of a virus-writing kid. As heavily overweight as he is tall, socially awkward, and with a reported history of mental problems, it turned out he liked listening to heavy metal music. The Blaster-B episode reads like a wayward rebellion of sorts.

Meanwhile, the originator of the Blaster code Parson modified for his own purposes, remains at large, despite a $250,000 bounty being placed on his or her head by Microsoft. In fact, Microsoft’s offer of a reward for informing on such people has yet to deliver a single capture.

“Jeffrey Parson is small fry when compared to the major virus-writing criminals who are still at large," commented Graham Cluley of Sophos, banging the nail on the head resoundingly.