Sophos reports new variants of the Mytob worm are spreading quickly by e-mail. The e-mails have subjects like "*DETECTED* Online User Violation", "Your Email Account is Suspended For Security Reasons", "Important Notification", "Account Alert" and also others.
If a user opens the attachment the virus will try to deactivate security software and will deny access to many popular security websites. It will also install a backdoor on the computer to give unauthorised and remote users access to the system.
The creators of Mytob appear to be a group of virus writers called Hellbot. Having more than one writer may aid them in issuing several different variants in short time periods.
"The Mytob source codes suggest that the virus writers are following a carefully planned strategy, whereby the routine allows the virus to develop." "By issuing many threats, all of which are tweaked slightly differently, they may be searching for the elements of their malicious code that will help them create a super worm."