war dialer

war dialer
 n.

   [originally from `wargames dialer', a reference to the movie War
   Games] A cracking tool, a program that calls a given list or range of
   phone numbers and records those which answer with handshake tones (and
   so might be entry points to computer or telecommunications systems).
   Some of these programs have become quite sophisticated, and can now
   detect modem, fax, or PBX tones and log each one separately. The war
   dialer is one of the most important tools in the {phreaker}'s kit.
   These programs evolved from early {demon dialer}s.