I am not an expert about clamav and systemd. I am not sure it is a good service file for clamonacc. I abandon using clamonacc as a service because of problem due to many accesses when starting clamonacc service. See https://bugzilla.clamav.net/show_bug.cgi?id=12660 I asked for clamav to supply a good service file but no answer. See https://bugzilla.clamav.net/show_bug.cgi?id=12670