We encountered this error recently when upgrading our ClamAV to 0.95 and ran into a problem where we got the error :
LibClamAV Warning: Cannot dlopen: file not found – unrar support unavailable
The solution to this is quite simple:
Create a symlink like so:
ln /usr/lib/libclamunrar_iface.so.6 /usr/lib/libclamunrar_iface.so
If you installed the x86_64 version, you need to run the following command:
ln /usr/lib64/libclamunrar_iface.so.6 /usr/lib64/libclamunrar_iface.so
Then restart clamav by running:
service clamd restart
If you encounter the same error, run ldconfig.