Norsk Hydro, one of the largest producers of aluminum in the world, said it was working to contain a cyberattack that impacted operations “in several of the company’s business areas,” sending shares in the company down 3.4% in early trading.
Shares recovered partially by midmorning.
The news also sent the price of aluminum up 1.2% on the London Metal Exchange.
The Norwegian National Security Authority said attackers used the LockerGoga virus, a ransomware virus that was linked to an attack on French engineering consultant Altran Technologies in January.
LockerGoga has not been widely used by criminal hackers.
“Hydro’s main priority now is to limit the effects of the attack and to ensure continued people safety,” the company said in a post on Facebook.
Norsk Hydro said it had shut down several of its metal extrusion plants that turn aluminum ingots into components for car makers, builders and other industries in response to the attack. It said smelters in Norway, Qatar, and Brazil were being operated manually. Its hydroelectric power plants were operating normally on IT systems that were not affected by the attack.
“Some extrusion plants that are easy to stop and start have chosen to temporarily shut production,” a spokesman for the company said.
“Hydro is working to contain and neutralize the attack, but does not yet know the full extent of the situation,” the company said in a statement.
In February, cyber security investigators said hackers working for the Chinese intelligence services had penetrated the network of Norwegian software firm Visma, as part of a global hacking campaign to steal intellectual property and corporate secrets.
Norsk Hydro’s Alunorte plant in Brazil was shut down after claims it was damaging the environment following a spill. The company’s shares have fallen nearly 40% in the last 13 months.