What is this?

[Hermite15]

files created by avast infecting your PCs you're kidding >>> no again there must have been references to infections in these temp files, explaining the detection by mbam.

[Hermite15]

And I don't know why Avast couldn't delete them.

Are you actually reading my replies? If something holds a lock on them, it can't delete them... Whether the lock is released later on is irrelevant, they'll stay there. Once again, disable the indexing for that directory and see whether the issue is gone.

well I doubt the OP has ever been playing with the index, and system folders (temp in Win in this case) are not indexed by default. If there's a lock on these files, it's from Avast.

[doktornotor]

well I doubt the OP has ever been playing with the index, and system folders (temp in Win in this case) are not indexed by default.

Well, they definitely are indexed by default on XP SP3. I just checked on a completely fresh XP install now. Fact being, the entire drive is indexed by default on XP installed on NTFS.

[Hermite15]

well I doubt the OP has ever been playing with the index, and system folders (temp in Win in this case) are not indexed by default.

Well, they definitely are indexed by default on XP SP3. I just checked on a completely fresh XP install now. Fact being, the entire drive is indexed by default on XP installed on NTFS.

yeah I was referring to Vista or Seven. But even on XP, must just be "allowed to be indexed", and not indexed at all. There was an old and completely outdated indexing system on XP that had to be purposely activated to index anything, made obsolete and replaced by Windows Desktop Search that would never have indexed system files/folders either by default.

edit: could you show a screen shot of what tells that windows folders are indexed on XP/SP3? don't know what interface you're referring to...

edit again: indexing wouldn't lock any file anyway

[doktornotor]

edit again: indexing wouldn't lock any file anyway

Yes, it does lock... Actually had this issue a couple of times with normal folder. Using the Unlocker utility, I found that I can't delete the file because it's locked by Windows indexer.

[DavidR]

Look at the VirusTotal links I posted, they are not FP's. How do I get rid of those nasties for good? And no, I don't have two AV's or any conflicting software (see my signature). Thank you!

avast unpacks or sends temporary files it is going to scan there, this _avast5_ folder should be cleared after a successful scan by avast. Why some files were left there after a scan is unknown.

You could have MBAM exclude the _avast5_ folder from scans, just in case there are any remnants of temporary unpacked files (periodically run a temp file cleaner or check to see if any files are regularly left behind). These files since they are in a different location and have a different file name to the original are effectively inert, but under normal circumstances they are removed after a successful completion of a scan.

[Bellzemos]

I deleted the files myself, rebooted and did a MBAM scan again - the infected files from Temp folder are gone and everything seems OK. Thank you all for your help!

[DavidR]

You're welcome.

I think it worthwhile to exclude that folder in MBAM and save yourself any heartache in the future.