Pro-Russian hackers took control of a Norwegian hydroelectric dam earlier this year, Norway’s intelligence agency admitted this week, the first time the country has blamed Moscow for the cyberattack.

The incident occurred on April 7, when hackers seized control of the Bremanger dam in western Norway. The hackers opened the floodgates of the dam, releasing more than 132 gallons (500 liters) of water per second for four hours before the attack was noticed and halted.

The Norwegian Police Security Service said the attack constituted a change in strategy for Russian-linked hackers. 

“Over the past year, we have seen a change in activity from pro-Russian cyber actors,” head of PST Beate Gangås said on Wednesday. “The aim of this type of operation is to influence and to cause fear and chaos among the general population. Our Russian neighbour has become more dangerous.”

She added that PST has recorded an increase in Russian intelligence operations in Norway. 

“Russian intelligence services spend significant resources identifying, cultivating and recruiting contacts in Norway. Norwegian citizens could be good sources of information for them,” Ms. Gangås said. 

Russia’s Oslo embassy called PST’s allegations politically motivated, asserting that “PST is unsuccessfully trying to substantiate the mythical threat of Russian sabotage against Norwegian infrastructure.”

The PST said a group of pro-Russian hackers posted a video on Telegram on April 7 claiming responsibility for the attack. The video reportedly contained the watermark of a Russian cybercriminal organization, but PST has not made the group’s name public. Norway’s National Criminal Investigation Service reported that it is aware of the group in question, adding that they have been linked to several cyberattacks in Western countries over the past few years.

The incident did not result in any injuries or serious damage to the dam, due to the low water level in the river. Most of Norway’s electricity is produced through hydroelectric dams, making attacks on its energy infrastructure particularly dangerous. 

In September 2024, the head of Britain’s Secret Intelligence Service, Richard Moore, warned that Russia was carrying out a “reckless” campaign of cyberattacks against European countries to scare leaders out of assisting Ukraine. Russia has denied Mr. Moore’s allegations.

• Vaughn Cockayne can be reached at vcockayne@washingtontimes.com.