How to Cause a Power Outage

Using war dialers to find modems connected to the programmable circuit breakers of the electric power control system, hackers could crack passwords that control access to the circuit breakers and could change the control settings to cause local power outages and even damage equipment. A hacker could lower settings from, for example, 500 A to 200 A on some circuit breakers; normal power usage would then activate, or "trip," the circuit breakers, taking those lines out of service and diverting power to neighboring lines. If, at the same time, the hacker raised the settings on these neighboring lines to 900 A, circuit breakers would fail to trip at these high settings, and the diverted power would overload the lines and cause significant damage to transformers and other critical equipment. The damaged equipment would require major repairs that could result in lengthy outages.