On Tuesday, August 9th 2005, Microsoft released a series of patches, one of which is for a serious exploit in the Plug and Play service that allows remote code execution. Within a few days, a new worm labeled as Zotob quickly infected Windows 2000 computers using Port 445, a Null session, and the Plug and Play exploit.
Today the newest variant, Zotob.E, quickly brought down computers at CCN, ABC, the New York Times, and San Francisco International Airport. The virus is also being identified as worm-rbot.cbq.