Watchdog

Watchdog is Detection/Alarm program designed to alert its owners to illegal entries into the system. It can do this by activating an external alarm or by sending a message to an occupied workstation. Netrunners can use Watchdogs to patrol another part of the Net, such as a rival's computer system, then key the Watchdog to run to their cybermodem or workstation if security is breached. This technique allows you to guard your secret files and pathways in other people's computers.

Source

 * Cyberpunk 2020, pg.138, 142