Hello,
Trojan.Zeroaccess!inf is a detection for files that are infected by Trojan.Zeroaccess.
Trojan.Zeroaccess Removal Tool
http://www.symantec.com/security_response/writeup.jsp?docid=2011-121607-4952-99
Zeroaccess is a threat Security Response has been keeping a close eye on for some time. In March the following whitepaper was released:
Trojan.ZeroAccess Infection Analysis
http://www.symantec.com/content/en/us/enterprise/media/security_response/whitepapers/trojan_zeroaccess_infection_analysis.pdf
This August blog may also be of interest:
Trojan.Zeroaccess.C Hidden in NTFS EA
https://www-secure.symantec.com/connect/blogs/trojanzeroaccessc-hidden-ntfs-ea
There are AV definitions and IPS signatures which can prevent Trojan.Zeroaccess from causing damage to a computer. (Please do be sure that IPS is in use in your organization- otherwise you are fighting with one arm ties behind your back!) Manual action is necessary once this trojan is in place. Luckily, for users of modern Windows OS's, this can be as simple as "restore previous version" of a file. More details:
http://www.symantec.com/security_response/writeup.jsp?docid=2012-080900-3758-99&tabid=3
Zeroaccess is a serious threat. A bit of public awareness can help admins to ensure their defenses are up.
I would also suggest you to create a case with Symantec Technical Support.
To Create a Case with Symantec Technical Support.
How to create a new case in MySupport
http://www.symantec.com/business/support/index?page=content&id=TECH58873
Phone numbers to contact Tech Support:-
Regional Support Telephone Numbers:
Australia: 1300 365510 (+61 2 8220 7111 from outside Australia)
United Kingdom: +44 (0) 870 606 6000
Hope this helps!!!