A quarter-million-dollar reward is available for information that leads to the conviction of the Mydoom worm’s creator.

The SCO Group yesterday said it is experiencing a distributed denial-of-service (DDOS) attack apparently related to the Mydoom worm that first appeared on Monday. The company also revealed it has been the target of several such DDOS attacks during the past ten months.

SCO is embroiled in legal action against IBM over intellectual property rights related to its ownership of System V Unix code, said it is offering a reward of up to $250,000 "for information leading to the arrest and conviction of the individual or individuals responsible for creating the Mydoom virus."

The current attack: "Is different and much more troubling, since it harms not just our company, but also damages the systems and productivity of a large number of other companies and organizations around the world," said SCO CEO Darl McBride in the statement. "The perpetrator of this virus is attacking SCO.

"We do not know the origins or reasons for this attack, although we have our suspicions," said McBride, who did not elaborate on what those suspicions are. "This is criminal activity and it must be stopped."

The company also said it is working with law enforcement authorities, including the Secret Service and FBI, to try to determine who might be involved in the attack.

The Mydoom worm, also known as Novarg and Mimail.R, is a mass-mailing worm that arrives via email as an attachment with one of several possible file extensions, including .bat, .cmd, .exe, .pif, .scr or .zip. When a user opens the attachment, his computer becomes infected. The worm is apparently designed to attack the company's Web site, www.sco.com, beginning on February 1.

Experts have said that the Mydoom worm is spreading faster than last year's Sobig.F, which topped the charts as the most widespread email worm of 2003.

Both Network Associates and Symantec said that when the attached file is executed, the worm scans the user's system for email addresses and forwards itself to those addresses. If the victim has a copy of the Kazaa file-sharing application installed, it will also drop several files in the shared-files folder in an attempt to spread that way.

According to Symantec, the worm also installs a "key logger" that can capture anything that is entered, including passwords and credit card numbers, and will start sending requests for data to SCO's Web site. If enough requests are sent, the SCO site could be forced offline.