I discovered apache2 logs it for each of my virtual domains being attacked by spambots. Looking into the directory of one my virtual domains
and doing a tail -f error_log
I saw an entry in the logs like:
[Mon Dec 15 22:23:05 2008] [crit] [client 18.104.22.168] mod_spamhaus: address 22.214.171.124.sbl-xbl.spamhaus.org is blacklisted. Deny connection to www.mysite.com
Very cool! It has help reduce the abuse directed to all of my hosted web sites
Thanks! Falko for putting up this how-to.