Can I just clarify what game people have been trying to update?

For me it was/is DOTA 2 and its vtex.exe thats getting flagged as the virus from the thread title.

I did a fresh install of DOTA 2, but the file was flagged again though it appeared to install correctly at least.

vtex.exe is part of the source engine and DOTA 2 runs that engine so thats likely a link.