For future reference, and for the benefit of people searching for
solutions to similar problems: You've made the most common rookie
mistake. You have already trashed potentially critical information
about the attack by trying to clean up the server first. Don't do
that.
Tim, while I do believe there is some truth in what you are saying here, I respectfully disagree in that this tends
to be a run-of-the-mill IRC bot as evidenced by the Undernet advisory. This looks like a skiddie-de-jour attack
against PHPMyAdmin and nothing to be concerned with regarding cloning disk images and full forensics. I do respect
your input and thoughts though for a more targeted attack; not an IRC bot in /tmp.