If you search the forum you’ll find several threads about this. I don’t think its been discovered why this happens but it appears to be a corrupt installation or vps file. Try repairing the avast! installation (while on line) or uninstall/reinstall.
To play it safe you could run a scan with Ewido, too.
OK guys, we’ve been chasing this mysterious problem for some time now. Hopefully, your help will contribute to finally finding out what causes it and how to fix it.
A couple of questions:
so, even a complete reinstall of the avast program does not fix the problem?
if so, please ZIP the whole avast folder (C:\Program Files\ALWIL Software), including subfolders, and upload it to ftp://ftp.avast.com/incoming (please note that you won’t have READ access to the ftp server, just write - so you won’t even be able to see what you’ve just uploaded).
BTW the virus is only detected during Web/Mail scanning, or even file system (on-access or on-demand)?
Hopefully, we’ll be able to simulate the problem in our lab (on a test machine).
I too have been plagued by this problem, but I may have narrowed down the culprit.
After unistalling and re-installing the program several times I finally switched off the automatic updating of both the program and VPS. I then installed an earlier version of 4.6 which I had downloaded a while ago.
Running the earlier version, with its associated out-of-date VPS, the problem disappeared. I then downloaded the VPS update executable and ran it separately rather than letting the program do it.
Everything still OK. This makes me suspect it’s something in the program update that’s causing the problem.
What I can say with certainty is that running version 4.6 (build November 2005, (4.6.731) ) with the latest VPS, 0611-2 seems to be stable.