Hello,
Could you please PM me your Tracking numbers?
Secondly in your case, it is advisable to follow few important steps:
1) Make sure all these machines are Patched with ALL Latest MS security patches and service packs.
2) Make sure the machines are installed with the Latest Symantec virus definitions.
3) Disable the Autorun Feature on the machine.
Preventing a virus from using the AutoRun feature to spread itself
http://www.symantec.com/business/support/index?page=content&id=TECH104447
Later, incase of suspicious activity still happening, then follow the steps provided in the Article below:
Using Symantec Help (SymHelp) Tool, how do we Collect the Suspicious Files and Submit the same to Symantec Security Response Team.
Hope that helps!!