My email server is using Postfix as the MTA and ClamAV as the anti-virus software running on CentOS 5.4. Today I check the version of Clamav installed on it and it is already out-dated so I need to upgrade to the latest stable version. The installed version of clamav is ClamAV 0.94 whereas the latest stable version is ClamAV 0.95.2.

Upgrading clamav installed on CentOS is easy. You just first backup the current configuration of clamav (/etc/clamd.conf and /etc/freshclam.conf).