No real solution to your problem here but...
A note on this particular virus.. One of the primary ways of spread is its ability to check for network shares, and once found, the .exe and .scr files on the "shared" directories are then infected as well. If you haven't already, strengthen the security for the shared directories..
In addition, since this particular virus can be dropped by other malware, it might be a good idea to check for spyware type issues by using the free removal tool below.. Performing a full cleanup with the tool might allow McAfee to install correctly. Still, on 11,000 machines, it might not be a workable solution.
http://www.majorgeeks.com/Malwarebytes_Anti-Malware_d5756.htmlI also found this information about the virus which provides some additional virus file names that could be on an infected computer:
http://www.threatexpert.com/threats/w32-sality-ad.htmlHope this helps.
Grif