W32.Mytob.CF@mm is a mass-mailing worm that uses its own SMTP engine to send an email to addresses that it gathers from the compromised computer.

The worm also opens a back door and spreads through the network by exploiting the Microsoft Windows DCOM RPC Interface Buffer Overrun Vulnerability (described in Microsoft Security Bulletin MS03-026) and the Microsoft Windows Local Security Authority Service Remote Buffer Overflow (as described in Microsoft Security Bulletin MS04-011).