North Korea offers US joint investigation of Sony cyberattack

North Korea has proposed a joint investigation with the United States into the hack attack against Sony Pictures, according to the state news agency, KCNA.

The offer comes as the FBI formally accused Pyongyang of the attack on Friday and US President Barack Obama promised to “respond proportionally” to the online breach.

North Korea says it can prove it has nothing to do with the cyberattack on Sony, the KCNA news release said.

An entrance gate to Sony Pictures Entertainment at the Sony Pictures lot is pictured in Culver City, California (Reuters / Fred Prouser)

An entrance gate to Sony Pictures Entertainment at the Sony Pictures lot is pictured in Culver City, California (Reuters / Fred Prouser)

The statement by Pyongyang also warns of “grave consequences” if Washington refuses to cooperate in the investigation of the attack and continues to accuse North Korea.

Sony’s network was hacked in November, with masses of private data, including employees’ emails, being made public.

The attack was followed by threats against movie theaters that planned to show “The Interview,” a comedy in which the US intelligence seeks to kill North Korea’s leader Kim Jong-un. Sony eventually refused to release the film.

Although North Korea has from the start denied being involved in the hacking and the threats, it still praised the cyberattack as a “righteous deed.”

A source in the White House recently told the Wall Street Journal that the US was considering redesignating North Korea as a state sponsor of terror. The country had spent 20 years on the terror black list before being taken off it in 2008 by George W. Bush.