War-Diallers

War-diallers are programs written by hackers to automate the hacking process. The program can be configured to call a series of telephone numbers to determine if any of the numbers are connected to a computer. These programs can also be configured to a dial a range of numbers to modems or fax machines

A hacker can program a war-dialler to dial hundreds of numbers in random patterns in an attempt to avoid detection. The war-dialler can recognize when a computer answers because of the unique tone of the answering modem. When the war-dialler finds a valid number of a computer, the program saves this information in a separate file.