Maybe someone with more familiarity on the topic can chime in, but I don't think it's the effective PR move you think it is. Nobody, I think, actually cares who from a blame perspective.

The idea that there's face saving to be had by blaming it on someone sophisticated just doesn't ring true to me. It still happened, the details specifically about who and how don't make your board, your boss, or Wall St. care.

It's way more relevant how you react to the breach, than it is that the breach took place.