The attack affected the 330 kilowatt electrical substation "North" at Pivnichna, outside the capital.[1] It happened a year after a previous attack on Ukraine's power grid.[1]
Dragos Security concluded that the attack was not merely to cause short-term disruption but to cause long-lasting damage that could last weeks or months.[3] The attackers had tried to cause physical damage to the station when the operators turned the grid back on.[3] The attack used Industroyer malware and has the ability to attack hardware including SIPROTEC protective relays.[3] These protective relays open circuit breakers if they detect dangerous conditions.[3] A security flaw meant that a single packet could put the relays in a state where it would be useless unless manually rebooted.[3] Siemens released a software patch in 2015 to fix the issue, but many relays weren't updated with it.[3] Evidence from logs obtained by Dragos Security showed the attackers initially opened every circuit breaker in the transmission station, causing a power cut.[3] Then an hour later they ran wiper malware to disable the station's computer, making it impossible to monitor the station.[3] Finally, the attackers tried to disable four of the stations SIPROTEC protective relays, which could not be detected by operators.[3] Dragos concluded that the attackers intended the operators to re-engergise the station equipment, which could have injured engineers and damaged equipment.[3] The data packets intended for the protective relays were sent to the wrong IP address.[3] The operators may also have brought the station back online faster than attackers expected.[3]
In April 2022, Ukrainian authorities announced that they had prevented a cyberattack that used malware similar to Industroyer.[4]