Mydoom Virus Variant Targets Microsoft Site

Mydoom, the worst e-mail virus since the SoBig worm in August, has spawned a second strain, dubbed Mydoom.B, that is programmed to attack Microsoft Corp.’s website.

Mydoom.B spreads an e-mail attachment that, once activated, will send waves of information requests to the Microsoft website in an attempt to shut it down, said Tony Magallanez, an engineer with security software maker F-Secure.

Mydoom.B is circulating in e-mail at a much lower rate than the first version, said Brian Dunphy, a director at Symantec Corp., the world’s biggest maker of anti-virus software.