Have you noticed slow Internet response this morning? Its probably due to the Welchia worm.
This is the coolest virus I've seen. It uses the same exploit that Blaster did to infect the same computers (if they haven't already been patched), but it's sole purpose is to hunt down Blaster and kill it. It not only cleans the computer of Blaster, it even downloads the patch from Microsoft to keep anyone else from using the same exploit.
--> Blaster worm
Welchia worm
How much you wanna bet that this is Microsoft thumbing their nose at the hacker?