Here is more info on the Zotob.
http://elamb.blogharbor.com/hacked/zotob.htm
The Zotob Worm has spread across three continents and has brought down systems at CNN, ABC and other networks. It is a decendant of Mytob. Zotob exploits the “plug and play” features of unpatched Win 2000 systems and earlier versions of Windows XP.
The Zotob Worm, like most worms, slows down network connectivity, can shut down/reboot a system, attempts to spread to other systems on the network and ultimately will connect with a remote server to allow downloads of more destructive malware such as virus’ and Trojans.
Zotob Worm Variants:
http://securityresponse.symantec.com/avcenter/vinfodb.html
Summary:
http://singe.rucus.net/blog/archives/510-MS05-039-and-the-Zotob-summary.html
http://singe.rucus.net/blog/archives/510-MS05-039-and-the-Zotob-summary.html