A “cyber event” interrupted grid operations in parts of the western United States last month, according to a cryptic report posted by the Department of Energy.
The March 5 incident lasted from 9 a.m. until nearly 7 p.m. but didn’t lead to a power outage, based on a brief summary of the electric disturbance report filed by the victim utility. If remote hackers interfered with grid networks in California, Utah and Wyoming, as the DOE filing suggests, the event would be unprecedented. A cyberattack is not known to have ever disrupted the flow of electricity anywhere in the United States, though Russian hackers briefly cut off power to parts of Ukraine in 2015 and again in 2016. DOE uses a broad definition of “cyber event,” describing it as any disruption to an electrical system or grid communication network “caused by unauthorized access” to hardware, software or data. That leaves open the possibility that a utility employee or trespasser, rather than a remote hacker, triggered the March 5 event.