Not a big deal, warn messages can be modified in:
/usr/share/qmail-scanner/locale/ (your lang)
I found that the messages for recipients (nl_NL) are wrong (BUG?)! The recipients get the message content for a sender of a virus (which is wrong). You can change that if needed.
recips_*** are warn messages configs for recipients
sender_*** are warn messages configs for the sender of a virusmail
Don't forget to run: qmail-scanner-reconfigure after each change.
Regards,
Bart