Hi,
It looks as if you might be infected. I don’t know why Avast! is detecting stuff in a Steam Folder. Could you find and upload vtex.exe to wikisend.com and send me the link so I can have a look?
If you’d like to check fro malware/viruses go here: http://forum.avast.com/index.php?topic=53253.0
Attach MBAM/OTL/aswMBR
aswMBR is for Windows 7 Only
Also, you’re using an outdated version of Avast!