The executable file is approximately 27,648 bytes in size. MyDoom.O might also spoof from the address, which is typically used to indicate a delivery failure, thus enhancing its social-engineering trickery. The sender’s “from” e-mail address is forged, and therefore does not indicate the true identity of the sender. MyDoom.O is a mass-mailing worm with an SMTP engine that sends e-mails to addresses harvested from infected machines. For many virus writers, success is not measured in millions of copies being sent it’s measured in the number of new computers hijacked for future use.” “We are now on the 15th variant of Mydoom, on the heels of multiple new Bagle variants. “Sadly, people and businesses fall prey to every one of these new virus variations, ensuring that new variants will be written and new systems compromised,” noted Mark Sunner, CTO of MessageLabs. This latest variant in the MyDoom virus family was first identified by MessageLabs at 4:40 ET July 26th 2004. MessageLabs, Sophos and Keynote Systems have released alerts about the new worm variant that has been circulating the Internet today and causing traffic slowdowns.

Google worm virus