there are lots of versions of the Zlob infection
the one YOU have may be known or unknown
I'd suggest that you update avast and then rt click on the ball and schedule a boot time scan
send any hits to the Chest- do not delete/remove
report back
The C:\Program Files\Alwil Software\Avast4\DATA\report\aswBoot.txt providers a more user friendly summary of the boot-time scan and it should list any detections.
post it back here
upload results to virus total and avast again
from David R
You could also check the offending/suspect file at: VirusTotal - Multi engine on-line virus scanner and report the findings here. You can't do this with the file securely in the chest, you need to extract it to a temporary (not original) location first, see below.
Create a folder called Suspect in the C:\ drive, e.g. C:\Suspect. Now exclude that folder in the Standard Shield, Customize, Advanced, Add, type (or copy and paste) C:\Suspect\* That will stop the standard shield scanning any file you put in that folder. You should now be able to export any file in the chest to this folder and upload it to VirusTotal without avast alerting.
If it is indeed a false positive, see
http://forum.avast.com/index.php?topic=34950.msg293451#msg293451, how to report it to avast! and what to do to exclude them until the problem is corrected.
if not a false positive or for further investigation
run a scan with Malware Bytes Anti Malware
any hits?
post the MBAM log in the Virus and Worms Forum here at Avast
with a link to your virus total results if any
and a link to this thread
do not panic or hose your OS just yet
good luck