universal keeloq

[stern0m1]

I see coming out of china universal remotes that can replace keeloq remotes. Any idea how they do it? I dont understand exactly the whole keeloq http://ww1.microchip.com/downloads/en/DeviceDoc/21137G.pdf works, but one thing is clear there is a unique manufactures code thats encrypted. Have they hacked all the manufactures codes?