https://github.com/s0h3ck/h3ck-c0ding/tree/master/CTFs/Qiwi-Infosec%20CTF%202016#ppc_400 (I know this one is late in time... HAAA! :p)

Original writeup (https://github.com/s0h3ck/h3ck-c0ding/tree/master/CTFs/Qiwi-Infosec%20CTF%202016#ppc_400).