I have some experience with Linux, currently running Ubuntu 14.04.2 LTS. I've disabled (a long time ago) root login - via ssh or webmin. I've changed my tomcat's username (good luck to the f**kers in china that is still trying "tomcat", "admin" or "root"). I have clamAv and maldetect running (finding nothing).
I do run a Tor exit node (I use Tor, I like to give back, not doing anything illegal, just valuing my privacy). So I can (like to try and) understand being black listed for running a Tor exit node - it is under my control but I get black listed for being hacked or have a virus or spamming or Natting for a trojan etc.
The latest one was CBL, I've looked at all their suggestion but can't find anything.
(I'm assuming that these services are not just adding me randomly): What should I look for?
Can the listing services pick up malware using my tor exit node? (If so, how do I block it?)