Bakdoor

A Bakdoor is basically the same as Baedeker's Net Map, with a twist—the program includes at least one and probably more passwords that allow it to route through private data systems. This is a very effective tactic, as a trace program will generally stop once it reaches a system, and most sentient operators will assume the intruder is operating out of the first system reached by a trace. Once the system owner is informed of the trace, the Bakdoor is usually found and the program's useless, so most pro 'runners save their Bakdoor for special runs. The program's variable cost depends on how many private system passwords are included in the program, and how powerful the owners of those systems are. A Bakdoor through Arasaka, for instance, would run into four figures, and few 'runners would bother wasting a valid Arasaka password on an anti-trace ruse.

Source

 * Rache Bartmoss Brainware Blowout, pg.83