I tried to activate the clamAV via WHM -> Manage Plugin -> clamAV Connector. But no luck there.
Turns out that while enabling the plugin it was unable to create the binary in the exact location as mentioned in the exim.conf file.
Later I tried to install it via yum.
# yum install clamd
# /scripts/restartsrv_clamd
# /scripts/restartsrv_exim
Worked fine for me. Everything looks fine now.
Hope it works for you as well.
Regards,
-Goodloo