According to a ZDNet article entitled:
A variant of MSBlast spread on Monday, but the new worm has an odd twist: It applies a patch for the vulnerability that it and other MSBlast worms use to infect Windows systems.
The new worm, dubbed W32.Welchia, W32/Nachi and Worm_MSBlast.D, appears to properly download the patch for both Windows 2000 and Windows XP from Microsoft’s Web site. Moreover, the variant will delete itself the first time an infected computer starts up in 2004.
Maybe this is a conspiracy by MS to make sure more people patch their machines? Or maybe a vigilante hacker who feels sorry for people?
Either way, the attacks against my poor little laptop are worse than ever, with one around every 10 seconds now :(.
[Link from ]