Nuclear plant hack resembles past North Korea attacks

South Korea would not rule out North Korea’s involvement in a recent cyberattack on a nuclear power plant that exposed sensitive data but has not endangered the plant’s reactors, Reuters reported.

An official told the news agency that the code used in the attack on Korea Hydro and Nuclear Power Co. Ltd. resembled previous North Korean cyberattacks on South Korean targets.

{mosads}“We cannot rule out or confirm North Korea’s involvement now, given the similarity of malignant codes patterns, and its verification will take some time,” the official said.

The incident has gained attention in the U.S. as cyber tensions between the U.S. and North Korea have escalated over a recent hack at Sony Pictures. The incident caused the movie studio to cancel the major theatrical release of a multimillion-dollar picture lampooning North Korean leader Kim Jong Un.

The FBI has blamed Pyongyang for the attack and the White House has vowed a proportional response. North Korea denies involvement in the attack and is threatening “counteraction” if the U.S. follows through with its promise.

Korea Hydro and Nuclear Power also said Tuesday it was investigating claims on Twitter that another batch of data had been leaked online, Reuters reported.

Because Twitter is a U.S. company, the South Korean official said it had reached out to U.S. officials to help investigate the claims, which included demands for money in exchange for stolen data.

South Korea is a frequent target for North Korean cyber warriors. Most prominently, Pyongyang hit a string of South Korean banks and media outlets in early 2013.