I had something similar. I was looking at my processes one day for some reason, when I noticed CuteFTP. Now, I knew what it was, but I knew for a fact that I hadn't installed it. Some investigation led to a hidden folder containing some scripts. One of them was for remote control via an IRC channel. So I hopped in the channel and had a chat with the user who was set to admin the bot on my computer.

Edit: Formatting.