I had a similar though a couple days ago. Not quite the same but imagine giving an Agent the task to hack other devices and steal their crypto coins / credit card number or anything with it can pay its token. Than install an agent in a harness with the same task. Establish some redundant communication channel, like message boards or whatever. So in the end there are several agents, on several hosts, consuming different APIs / LLMs and communicating with each other over different channels. Basically the same concept as OpenAI explained when their LLM hacked huggingface but in this scenario their not bound to a single sandboxed environment but spread over the internet. If such a swarm has reached a critical mass it would be pretty dificult to erase them as its impossible to control every inference engine or LLM API endpoint.
In the end its the next evolution step from computer viruses, worms and trojans. So I propose we will call those "ghosts". I.e. a ghost is when a rogue llm takes control over a victims host.