It's highly unlikely the North Korean government was ever involved in any hacking - it's all political propaganda to manipulate public opinion. A foreign government would have bigger fish to fry than bother with some here-today-gone-tomorrow piece of throwaway entertainment beyond stating their personal dissatisfaction The US has refused to take up NK's offer to work together to find the hackers because the US knows the Korean government aren't involved, but wants to maintain the fiction to further its political interests This is a standard policy used again and again with foreign countries over the years