I've got this on my pc twice in the last week. Cleaned it out with Norton.
VIRUS ALERTS - March 26, 2005
W32/Mytob-K
Summary
Type Worm
W32/Mytob-K is a mass-mailing worm and backdoor Trojan that targets users of Internet Relay Chat programs.
W32/Mytob-K is capable of spreading through email and through various operating system vulnerabilities such as LSASS (MS04-011).
W32/Mytob-K harvests email addresses from files on the infected computer and from the Windows Address Book.
Side effects
* Turns off anti-virus applications
* Allows others to access the computer
* Modifies data on the computer
* Deletes files off the computer
* Steals information