NetBus

NetBus or Netbus is a software program for remotely controlling a Microsoft Windows computer system over a network. It was created in 1998 and has been very controversial for its potential of being used as a backdoor.

NetBus was written by Carl-Fredrik Neikter, a Swedish programmer in March 1998. It was in wide circulation before Back Orifice was released, in August 1998. The author claimed that the program was meant to be used for pranks, not for illegally breaking into computer systems. Translated from Swedish, the name means "NetPrank".

However, use of NetBus has had serious consequences. In 1999, NetBus was used to plant child pornography on the work computer of Magnus Eriksson, a law scholar at Lund University. The 3,500 images were discovered by system administrators, and Eriksson was assumed to have downloaded them knowingly. Eriksson lost his research position at the faculty, and following the publication of his name fled the country and had to seek professional medical care to cope with the stress. He was acquitted from criminal charges in late 2004, as a court found that NetBus had been used to control his computer.

There are two components to the client-server architecture. The server must be installed and run on the computer that should be remotely controlled. It was a .exe file with a file size of almost 500 KB. The name and icon varied a lot from version to version. Common names were "Patch.exe" and "SysEdit.exe". When started for the first time, the server would install itself on the host computer, including modifying the Windows registry so that it starts automatically on each system startup. The server is a faceless process listening for connections on port 12345 (in some versions, the port number can be adjusted). Port 12346 is used for some tasks.

The client was a separate program presenting a graphical user interface that allowed the user to perform a number of activities on the remote computer. Examples of its capabilities: