Well, why would anyone want to hack Sony and make threats to get them to not release this particular film, if it were not the North Koreans?
It might have been the Chinese, doing a favor for the Norks, but nothing else seems to make any sense.
I wouldn't put this kind of cheap stunt past our own State Department, NSA, and administration run by our Douchebag in Chief. After all, they blamed the terrorist attack in Benghazi on a YouTube video.