3.4. Updating Defs

Now we need to update our virus definitions. Clamscan includes a utility, freshclam, to take care of this. Freshclam automatically changes from root to the clamav user that you created during the installation. First, create a log file that freshclam can log to.

#touch /var/log/clam-update.log
#chmod 600 /var/log/clamupdate.log
#chown clamav /var/log/clamupdate.log

Now start freshclam:

#freshclam -d -c 6 -l /var/log/clam-update.log

This checks for a new virus definition database six (6) times a day. Check the /var/log/clam-update.log file. It should look something like this:

ClamAV update process started at Wed Jan 28 17:49:48 2004
main.cvd is up to date (version: 19, sigs: 19987, f-level: 1, builder: ddm)
daily.cvd updated (version: 111, sigs: 597, f-level: 1, builder: tomek)
Database updated (20584 signatures) from database.clamav.net (

Now add the freshclam -d -c 6 -l /var/log/clam-update.log to your startup scripts.

You can also setup a cronjob to update the Defs every 6 hours, if you like.

#vi /etc/crontab

0 6 * * * root /usr/local/bin/clamscan