I have to run clamav in machines that don’t have access to internet, but they have access to intranet. I downloaded the virus db files manually from
https://www.clamav.net/downloads and then distribute them to /var/lib/clamav folder in the target machines. It fails with "LibClamAV Error: Can't load /var/lib/clamav/daily.cvd: Can't verify database integrity”.
However, if I use the db files generated from freshclam and distribute them to /var/lib/clamav folder in the target machines, it works.