Avast reports Win32:Agent-COH Trojan in vmdk file (VMware Virtual Machin)

[Nate.Don]

Here's my problem:

I've been working with this vmdk, (a VMWare Virtual Machine file that hosts a Windows 2003 Server) for 4+ months without any report from Avast.

I've been running Avast 4.8 with latest updates all this time.
It was only today, while shutting down the Virtual machine file (which was applying some security updates to the hosted Windows 2003 Server OS), that Avast reported a Win32:Agent-COH [Trj] found in the file. It can't be repaired. Only deleted.

I chose to ignore it for the time being, because I'm doing serious development work on the Virtual Machine and really can't afford to delete it now without being sure it's infected.

I upgraded Avast  to 5.0.418 and scanned the file. Again it reports the same Trojan, Win32:Agent-COH [Trj] with "High" severity.

I've noticed in some older posts that Avast did report Trojans (though not this particular one) on vmdk files.

So, is this a false positive? Is the file really infected ? Should I just put the .vmdk extension in the scan exceptions?

[Pondus]

can you upload the file to VirusTotal    www.virustotal.com   when you have the result, copy the URL in the addressbar and post it here

[Nate.Don]

It's very hard to do that because this vmdk file is 25GB.
(all virtual machine host files are quite large).

[Pondus]

well yes, i think the VirusTotal limit is 20mb.......