Isn't this against Blockland rules or something? I'd report him to Badspot.
However if a add-on is posted to the pubic and has the backdoor admin exploit, it is immediately a red flag and is automatically placed in the fail-bin, this has happened two times already in the past, one was when JJstorm (Which I heard that his key got revoked for doing this) released his CityRPG mod and has been detected to have a backdoor admin exploit, and another add-on that was posted about 2-3 years ago or so that was some sort of "Parachute mod".