Fox NewsNorth Korea, Angrily Denying Sony Attack, Proposes Joint Investigation With USNew York TimesTokyo — Warning of “serious consequences” if the United States retaliates against it, North Korea on Saturday insisted that it was not behind a damaging cyberattack on Sony Pictures, and offered to prove its innocence by proposing a joint investigation with ...North Korea says it's not involved in Sony hack; proposes joint probe with USFox NewsN.