clamd will not run as root if User root is set in /usr/local/etc/clamd.conf. It seems this is because /usr/local/etc/rc.d/clamav-clamd sets the default user as clamav. The only way to set clamd to run as root is to add clamav_clamd_user="root" in /etc/rc.conf and then the User <username> line in clamd.conf is honored. The line in /usr/local/etc/rc.d/clamav-clamd: : ${clamav_clamd_user="clamav"} can alse be commented out and then the User root line in clamd.conf is honored. Not sure when the rc.conf option was added, but it doesn't seem to be documented anywhere. Please bring back the original behavior.
ping maintainer again.