Russia’s top oil producer Rosneft said a large-scale cyberattack hit its servers on 27 June, and computer systems at some banks and the main airport in neighboring Ukraine were also disrupted.
A Moscow-based cybersecurity firm, Group-IB, said it appeared to be a coordinated attack simultaneously targeting victims in Russia and Ukraine.
In Copenhagen, global shipping firm A.P. Moller-Maersk said it had suffered a computer system outage caused by a cyberattack, though it was not immediately clear if it was connected.
One of the firms Group-IB said had been hit in Russia, Damco, is Maersk’s logistics company.
The latest disruptions follow a spate of hacking attempts on state websites in Ukraine in late 2016 and repeated attacks on its power grid that prompted security chiefs to call for improved cyberdefenses.
Rosneft, one of the world’s biggest producers of crude oil by volume, said its oil production had not been affected.
“The company’s servers underwent a powerful hacking attack,” the company said on Twitter.
“The hacking attack could lead to serious consequences, but the company has moved to a reserve production processing system, and neither oil output nor refining have been stopped.”