I actually believe it's referring to Assassin's Creed 2. It had to check in with the central server to see if a legitimate copy was being played, and the way it was cracked was basically going through every possibility where the check can fire off, recording the request/response, and having the cracked version play back the appropriate response to the request. It basically had to be exhaustively played to get to a point where all the request/response combinations got recorded.
A lot of DRM (eg the one by denuvo) could be bypassed with hooking from kernelmode, hypervisor shenanigans etc.
But that doesn’t comply with the „scene rules“, they always want a clean executable without any background services. I was always impressed by Razer1911 and CPY who obeyed these rules and did all this work just for clout.
