Microsoft Deflects Mydoom Attack

Microsoft says it has yet to be affected by a Mydoom-B worm-induced distributed denial of service attack, which antivirus software companies predicted would be fairly easy for the software company to fend off.

Unlike The SCO Group's site, which has been assailed by a denial of service attack from Mydoom-A worm since Sunday and continues to fight off attacks from both the A and B variant of the Mydoom worm, a Microsoft spokesperson says that "everything on the Microsoft site seems to be working fine."

The Mydoom-B worm is similar to the Mydoom-A worm, but contains an added DOS attack against Microsoft's Web site and a feature that blocks access to antivirus Web sites on infected machines.

According to the code in the worm, the DOS attacks against SCO, a Unix vendor based in Lindon, Utah, are scheduled to continue through February 12.

Well Prepared

Microsoft has classified the second variant of the worm as a moderate threat and says it has been well prepared for the DDOS attack which it expected to begin on Sunday, the spokesperson says.

"Although Microsoft is unable to discuss the specific remedies it is taking to prevent the reported DDOS attack, we are doing everything we can to ensure that Microsoft properties remain fully available to our customers," the Redmond, Washington, company says on its Web site. "Microsoft is aggressively working with our Virus Information Alliance partners to help protect customers from this outbreak."

The Mydoom-B worm is generally considered by leading antivirus software companies and e-mail security firms to be less effective than Mydoom-A at propagating itself and causing widespread damage to computer systems. London-based Sophos on Tuesday says it has received very few reports of actual Mydoom-B infected computers.

Only an Afterthought?

The small number of reports of Mydoom-B suggests that the attack on Microsoft will fail, according to Graham Cluley, senior technology consultant at Sophos.

"There was only about a day's separation between Mydoom-A and Mydoom-B, so it's my guess that the real target of the virus writer was SCO while an attack against Microsoft was something of an afterthought," Cluley says. "When it comes to being able to spread itself, Mydoom-B didn't get as lucky as Mydoom-A, which still poses a significant threat."

Although both SCO and Microsoft are offering rewards of $250,000 each for information leading to the arrest and conviction of the person or persons responsible for creating and releasing both versions of the Mydoom worm, Cluley sees little chance the money will lead to an arrest.

"It is a long shot, to be honest, but bounties or rewards don't do any harm either and may actually discourage virus writers in the future as it shows companies are serious about catching those responsible," Cluley says. "If virus writers know there is a strong cash incentive for someone to grass them up, they may think twice about unleashing a virus."