I installed clamav on my openbsd notebook because I decided I needed clamav for when friends ask for help.
Trying to get the current database resulted in the message
ERROR: Please edit the example config file /etc/clamav/freshclam.conf
ERROR: Can't open/parse the config file /etc/clamav/freshclam.conf
A quick scan through the configuration file didn't reveal any particular problems that I noticed. (If it had been a snake, it'd have bitten me.) No file ownership or permission issues.
Searching the web sent me to lots of answers like this:
Comment out the "Example" directive on the third or fourth line of the file.
The clamav team really wants you to at least look in the file, I guess.
Not a bad idea.
I'm downloading the current database now. Next step is to write an image of this to the bootable USB drive.