Because not believing, with little evidence, NK is competent enough to pull this off makes you a B357 K0r34n 1337 h4xx0r.
What on earth makes you think that NK has to have the native talent? The didn't figure out how to make nukes on their own either. They didn't home-grow their substantial currency counterfeiting operation, either. They likewise don't design and build their own military equipment. But that doesn't stop them from having nukes, from doing big business in phony currency, and sinking other people's ships.