Blaster/Sasser.variant Worm is a Worm that is not really a Worm. Blaster/Sasser.variant appears to be a fake security warning from rogue antispyware WindowsAntivirus2008. After WindowsAntivirus2008 scan computer system with his fake scan it show user this type of message:

“WARNING! Attack Detected.
Possible harmful action has been detected from remote host.
Windows Antivirus 2008 has detected possible harmful actions from remote computer on the network. Blaster/Sasser.variant worm behavior detected. You have to register your copy to get full protection feature set and an ability to defeat upcoming threats. To begin online registration, please click “Activate now” button below.”

So Blaster/Sasser.variant Worm isn’t really a "Worm" this is just a WindowsAntivirus2008 fake warning message. This way WindowsAntivirus2008 wants to trick users into buying "full" version of their program. So the only thing that you have to worry about is the WindowsAntivirus2008 rogue antispyware program. Don't be tricked by WindowsAntivirus2008 program and delete it as soon as possible!