New Mass-Mailing Worm Surfaces

The worm, Maldal.D, was written and distributed on Dec. 28, according to Symantec. Written in Visual Basic, the worm spreads through Microsoft Outlook and tries to delete antivirus software and other files.

Maldal.D arrives as an e-mail that uses the name of the infected computer in the subject line and the attachment's file name, according to Trend Micro. The body of the e-mail is randomly selected from several lines, including "Test this game," "I wish u like it" and "Surprise!!!"

Maldal.D is a variant of the Zacker.C worm from earlier this month, according to Vigilinx, a security-services firm in Parsippany, N.J.

McAfee, the antivirus division of Network Associates, said it received only a few samples of the worm and rated it a low risk. Trend Micro also ranked it a low risk, while Symantec rated it a moderate risk.

Security firms advised users to update their antivirus software to prevent infection from Maldal.D.