DavidR
2
Not too unusual as that is where avast unpacks/sends copies of files to be scanned. However to determine if it were a good or bad detection you would need to send it to VirusTotal - Multi engine on-line virus scanner and report the findings here, post the URL in the Address bar of the VT results page.
So I assume that you are using MBAM Pro ?
Add the c:\windows_avast_ folder to the MBAM Ignore List.
The problem being that when MBAM intervenes in this folder it actually stops avast from scanning that file, which is bad as if it is infected, avast can’t alert on the ‘original file’ not this copy. This is why it is important to exclude this folder in the MBAM Ignore List.