Back Orifice

Back Orifice

Developer(s)	Sir Dystic (cDc)
Stable release	1.20 / August 3, 1998
Operating system	Microsoft Windows, UNIX-systems (client only)
Type	Remote administration
License	Freeware, (source distribution, UNIX client)
Website	Back Orifice Homepage

Back Orifice (often shortened to BO) is a computer program designed for remote system administration. It enables a user to control a computer running the Microsoft Windows operating system from a remote location. The name is a play on words on Microsoft BackOffice Server software. It can also control multiple computers at the same time using imaging.

Back Orifice was designed with a client–server architecture. A small and unobtrusive server program is installed on one machine, which is remotely manipulated by a client program with a graphical user interface on another computer system. The two components communicate with one another using the and/or network protocols. In a reference to the Leet phenomenon, this program commonly runs on port 31337.

The program debuted at DEF CON 6 on August 1, 1998. It was the brainchild of Sir Dystic, a member of the U.S. hacker organization Cult of the Dead Cow. According to the group, its purpose was to demonstrate the lack of security in Microsoft's operating system Windows 98.

Although Back Orifice has legitimate purposes, such as remote administration, there are other factors that make it suited for less benign uses. The server can hide itself from cursory looks by users of the system. As the server can be installed without user interaction, it can be distributed as payload of a Trojan horse.