The viruses are largely alike: They are designed to spread by attaching copies of the program to e-mail messages and download additional features from compromised Web sites. Moreover, they are all difficult to clean from an infected Microsoft Windows-based PC, because they stop the system from connecting to antivirus Web sites to download updates.
The fact that several similar variations of MyDoom have been released in quick succession suggest that a more lethal version may be in the works, said Sam Curry, vice president of product management for Computer Associates International's eTrust software.
MyDoom spawns four small offshoots. This news on MSN Tech and Gadgets says that these new variants could also be a harbinger of a more lethal version about to hit the web users.