A thread here revealed Avast! completely missed an “in the wild” infection here: (link is to a thread here in this forum) http://forum.avast.com/index.php?topic=96915.0
You will need to go to reply # 22 and be logged in to see the details under ESETSSCAN.txt. Note that the scan was run without quarantining the malicious files, which was a good thing.
Would seem to me that Avast! would, under the auspices of running a full online scanner, would have the opportunity to see and examine malicious files they otherwise might not see.
DonZ63 says that apparently only Microsoft and eSet currently detect this threat.
Very surprised Avast! did not detect this.