Microsoft is offering a quarter-million dollar reward for information leading to the capture and conviction of the damaging Mydoom.b worm's creator, the company announced last night.

The offer is part of Microsoft's $5 million bounty program to reward people for information relating to worm and virus authors, announced last November.

The Mydoom.b worm is similar to the Mydoom.a worm that appeared on Monday, but additionally contains a scheduled denial of service (DOS) attack against Microsoft's Web site and a feature that blocks access to anti-virus Web sites on infected machines.

According to Microsoft, the attack against the Web site is scheduled for February, which begins on Saturday. The company is working with the FBI, Secret Service and Interpol in investigating the worm.

Residents of any country are eligible for the award, Microsoft said.