This threat is classified as a mass-mailing worm. A mass mailing e-mail worm is self-contained malicious code that propagates by sending itself via e-mail. Typically, a mass mailing e-mail worm uses its own SMTP engine to send itself, thus copies of the sent worm will not appear in the infected user’s outgoing or sent e-mail folders. This threat is detected by the Microsoft antivirus engine. Technical details are not currently available.