I'd say the NSA have been developing and training custom LLMs for at least 12 months now. They have the means, and they have the history. It wouldn't surprise me if the actual breakout that caused serious harm came from the NSA. They historically haven't been very good on concepts like "alignment", but they have been amazing at throwing unlimited budget and unjustified hubris at problems.

If various military groups are already publicly saying that they relied too heavily on ai, then I'd hate to see what the group with the pertinent resources and the culture of absolute secrecy is getting up to.