ClamAV - Reset Defs DB
Sometimes ClamAV will download a virus update, and the MD5 will be wrong. If it is, then ClamAV usually goes down, and the system suspends delivery. In which case it's time to refresh your defs.
You'll know this is the case if you go to the /var/log/zimbra.log and you see that ClamAV isn't running, postfix/qmgr errors out at 'delivery temporarily suspended', messages like 'malformed database' in /opt/zimbra/log/clamd.log, and by checking zmclamdctl status.
Other symptoms are, if you stop & restart Zimbra services (zmcontrol stop and zmcontrol start), antivirus may fail to start with the errors (among others):
WARNING: Your ClamAV installation is OUTDATED! and clamd failed to start
The above text is part of a much longer set of errors; despite what the Clam errors say, you DON'T necessarily have to update your whole ClamAV.
ClamAV Virus definitions update automatically every 2h by default (zimbraVirusDefinitionsUpdateFrequency attribute).
Zimbra updates the ClamAV engine to latest with every release of ZCS & does not endorse edorse doing so on your own but you can find directions here: ClamAV - Updating Version Out of cycle updates RFE is Bug 15137
To fix this, you can delete the defs and try again:
su - zimbra mkdir /tmp/clamdb mv /opt/zimbra/clamav/db/* /tmp/clamdb zmprov ms `zmhostname` +zimbraServiceEnabled antivirus /opt/zimbra/clamav/bin/freshclam --config-file=/opt/zimbra/conf/freshclam.conf zmantivirusctl stop zmantivirusctl start
(zmantivirusctl incorporates zmclamdctl/zmamavidsctl/zmmtaconfigctl though you can just restart ClamAV individually)
In ZCS 5.0.3+ we moved to a data directory to keep separate from application data, replace the above with:
Verify by running:
/opt/zimbra/clamav/bin/clamscan -d /opt/zimbra/data/clamav/db/