Didn’t work here either (Ubuntu 12.04LTS):
FYI: I just had to start the deamon.
Looks like Virtualmin can’t start it.
But this worked:
/etc/init.d/clamav-daemon start
(here too, there is no /etc.init.d/clamd )
I then also had same issue with Spamassin not getting started properly by Virtualmin’s setup wizzard, but this fixed it:
/etc/init.d/spamassassin start