W32.Lirva.C@mm

NOTE: Due to a decreased rate of submissions, Symantec Security Response has downgraded this threat from a Category 3 to a Category 2 as of February 28, 2003.

W32.Lirva.C@mm is a mass-mailing worm that also spreads by IRC, ICQ, KaZaA, and open network shares. It is a variant of W32.Lirva.A@mm. This worm attempts to terminate antivirus and firewall products. It also emails the cached Windows 95/98/Me dial-up networking passwords to the virus writer.

The worm connects to a Web site on web.host.kz/ and downloads BackOrifice, which it executes. W32.Lirva.C@mm also attempts to download another file, which is currently not present on the Web site.

When Microsoft Outlook receives the worm, it takes advantage of a vulnerability that allows the attachment to auto-execute when you read or preview the email. Information on this vulnerability and a patch can be found at http://www.microsoft.com/technet/security/bulletin/MS01-020.asp.

If the day of the month is the 7th, 11th, or 24th, the worm will launch your Web browser to www.avril-lavigne.com and display a graphic animation on the Windows desktop.




As with many other worms, this worm takes advantage of a vulnerability that allows the attachment to auto-execute when you read or preview the email. Information on this vulnerability and a patch can be found at http://www.microsoft.com/technet/security/bulletin/MS01-020.asp.