Back Orifice
From Encyclopedia Dramatica
Back Orifice is a program created by the Cult of the Dead Cow to let them moar easily h4x0r j00r b0x0r. It consists of two pieces: a server part that installs when you open that email from Grandma entitled "FLUFFY BUNNY PICS WEBSITE #56" but see a bunch of gibberish instead, and a client part that someone runs on another computer and uses to pwn you. It runs on port 31337 (lol get it?). Ur infoz promptly lay in the hands of the evildoers.
Because it was created before the world changed, it is widely assumed that Back Orifice was a major player in the hijacking of Oceanic Flight 815.
The new version of Back Orifice, designed in 2006, is designed more as a RAT, a "Remote Administration Tool." All this "administration" is bullshit, RATs are only used to screw with people. They main feature of the new Back Orifice is a keylogger, used to read everything you type and steal all your shit. Other funny shit commonly found in RATs is stuff like freezing the mouse and turning off the keyboard.