Yeah I've run into this sort of thing at work. One parrticuarlly memorable one was "PS Guard". Which was a rogue Security software. Acted like a normal antivirus, when what it really did was install crap on your PC, which it then asked for money to remove, as the PS guard was a trial version or some such crap. As i recall, searching for the individual entries PS Guard reported, also led to specialized software that would remove it for a fee. Was a pretty nice money grabbing circle jerk with this gurella ware that refused to go away as the pivot man. Umpteen entries in the system regestry, DLL files, etc.. It was a royal bitch to get rid of it.
Couple wiki entries for further reading:
http://en.wikipedia.org/wiki/Rogue_security_software
http://en.wikipedia.org/wiki/List_of...urity_software