How so I terminate an unknown local agent?

We can’t because there is still a process that is pinging Prefect cloud. If you delete it from the UI, it will still ping.

What do you mean when you say unknown? Are you the only person who has access to your Prefect Cloud account? Is this some unsolicited actor? If so, how could that happen - did you commit the API keys to a public repository? You may delete your existing API keys and create new ones to ensure nobody who is unauthorized is able to start a new agent Perhaps it's just an agent started on your local machine or VM - can you check whether ad02... is your hostname?

I started agents on local machine, docker container in local machine and AWS ECS, I thought it may be a runway process. I’ll check with co-worker who may have use my API key.

Great to hear it's not a security issue. Keep us posted!