Microsoft is currently investigating reports of a variant of the Mydoom mass mailer worm called MyDoom.O. You can help protect yourself against this Mydoom variant by updating your antivirus softwar
For additional information and resources on Mydoom.O (also referred to as Mydoom.L and Mydoom.M), check the Web sites of the following antivirus software vendors participating in the Microsoft Virus Information Alliance:
For more detail click the following link..
http://www.microsoft.com/security/incident/mydoom.mspx