A Zeroaccess paper from Symantec http://www.symantec.com/content/en/us/enterprise/media/security_response/whitepapers/zeroaccess_indepth.pdf (the link is direct but is within the Symantec / Norton sites)
It appears not to include the latest major change and there are some other pieces I scratch my head over like the appearance date. But Oh well
Quads