Note that we also provide write-ups and files for CTFs in 2013 [0], 2014 [1] and this year [2]. If you don't know what CTFs are:
https://ctftime.org/ctf-wtf/[0]: https://github.com/ctfs/write-ups-2013
[1]: https://github.com/ctfs/write-ups-2014
[2]: https://github.com/ctfs/write-ups-2016