For nearly three years, the December 2016 cyberattack on the Ukrainian power grid has presented a menacing puzzle. Two days before Christmas that year, Russian hackers planted a unique specimen of malware in the network of Ukraine’s national grid operator, Ukrenergo. Just before midnight, they used it to open every circuit breaker in a transmission station north of Kyiv. The result was one of the most dramatic attacks in Russia’s years-long cyberwar against its western neighbor, an unprecedented, automated blackout across a broad swath of Ukraine’s capital.
But an hour later, Ukrenergo’s operators were able to simply switch the power back on again. Which raised the question: Why would Russia’s hackers build a sophisticated cyberweapon and plant it in the heart of a nation’s power grid only to trigger a one-hour blackout?
A new theory offers a potential answer. Researchers at the industrial-control system cybersecurity firm Dragos have reconstructed a timeline of the 2016 blackout attack based on a reexamination of the malware’s code and network logs pulled from Ukrenergo’s systems. They say that hackers intended not merely to cause a short-lived disruption of the Ukrainian grid but to inflict lasting damage that could have led to power outages for weeks or even months. That distinction would make the blackout malware one of only three pieces of code ever spotted in the wild aimed at not just disrupting physical equipment but destroying it, as Stuxnet did in Iran in 2009 and 2010 and the malware Triton was designed to do in a Saudi Arabian oil refinery in 2017.
In an insidious twist in the Ukrenergo case, Russia’s hackers apparently intended to trigger that destruction not at the time of the blackout itself but when grid operators turned the power back on, using the utility’s own recovery efforts against them.