It's a (failed) case study in "what if we backdoor it in a way only good guys can use but bad guys can't?"

Computers don't know who's / what's good or bad. They're deterministic machines which responds to commands.

I don't know whether there'll be any clues about who did this, but this will be the poster child of "you can't have backdoors and security in a single system" argument (which I strongly support).