It appears that there is a vulnerability in our configuration. I believe someone got into our server via a bulletin board program (we deleted program). But control panel runs SLOOOOWWW. CPU usage very high. I found files via Cpanel, System Health, with oodles of processes running httpdse. Clicking on one, it was from "nobody". I found this post about another CMS, Joomla, that sounds like the same problen I have:
http://www.heise-security.co.uk/news/75459

Thing is, how do I fix this in Xoops? Has anyone else had similar security leaks?

This is a server related issue, definately not one you can fix with a script like XOOPS. You hosting provider and/or system admin need to solve this!

Herko