Check ClamAV daily.cvd plugin for Nagios

The plugin is simple and is written in Perl. It basically checks the version of
the ClamAV signature database installed on the system, and compares it against
the latest version that ClamAV is advertising on their site. It's interesting
the way the signature version is reported; they publish the version information
in a DNS TXT resource record. So the plugin does a DNS query and compares the
result to the local ClamAV version.