[https://infosec.rm-it.de/2018/04/01/nuit-du-hack-ctf-2018-coingame/](https://infosec.rm-it.de/2018/04/01/nuit-du-hack-ctf-2018-coingame/)

Original writeup (https://infosec.rm-it.de/2018/04/01/nuit-du-hack-ctf-2018-coingame/).