Alarm systems and panels were designed before the prevalence of wireless technology and communicate with a proprietary protocol over a two-wire data bus. This bus was designed for use between alarm panels, keypads and zone expanders. However this has now been extended to allow the system to communicate with wireless sensors. Unfortunately, little research has been performed regarding these systems, and operational information about them is scarce and often incorrect. This presentation will demonstrate several classic vulnerabilities of alarm installations and then present several new techniques for reducing the effectiveness of the alarm system.