For all the hot air about "analysis" and "evidence" and crimes NK committed when Kim was a baby five presidents ago, it's extremely easy to know North Korea wasn't responsible for this:
Because the idea that any nation state could function in any capacity while simultaneously being so broke that a puny act of organized crime involving Bitcoins could make any difference is utterly beyond the realm of absurdity.
Nobody with even moderate critical faculties can seriously believe such a ridiculous premise, and the only thing anyone does by arguing it, sincerely or otherwise, is reduce their own credibility.