Before LLMs got good enough to do this, lots of people were dismissive of their capabilities and didn't take seriously the idea that this was a risk to protect against.
Then again, before LLMs, people were saying that obviously nobody would be dumb enough to put an AI on the internet where it could hack anyone, clearly we'd keep it in a box, don't listen to that Yudkowsky guy who says he did an experiment where he role-played as an AI and convinced people to let him out.
Regardless, this should be interpreted in the same kind of way as "During our live-fire exercise in which our F-15s were armed with AGM-88 High-speed Anti-Radiation Missiles, a member of the local police force was curious about how fast our aircraft were travelling and pointed a speed gun at the aircraft. The speed gun did not respond to IFF pings from the F-15. Fortunately, while the missile was active for this test, only a dummy warhead was loaded."
(This example is based on a similar story which may well be urban legend; obviously there are many differences, the point I make here is that yes, people do perform live-fire tests, and unfortunately there is never zero risk while testing things).
> I would expect more responsibility from a government agency.
I have read the prompts in the linked report; If I was not already familiar with Yudkowsky/LessWrong literature about instrumental goals, misaligned incentives, reward hacking, that capability is a separate axis to morality, etc., it would not be obvious to me that an agent would interpret those prompts in a way that has "spread malware" as a potential step in the middle of the attempt.