HACKvent 2018 https://hackvent.hacking-lab.com
SANS Holiday Hack Challenge 2018 https://www.holidayhackchallenge.com/2018
GreHack 2018 https://2018.challenge.grehack.fr writeup https://www.synacktiv.com/posts/challenges/grehack-2018-qual...
CSAW Red Team Competition 2018 https://red.csaw.io/challenges
Hacktober.org https://hacktober.org
Advent Calendar of Advanced Cyber Fun 2018 https://xmas.rip repository https://github.com/takeshixx/advent-calendar-2018 writeup https://gist.githubusercontent.com/BenGardiner/03e2a7edeb764... writeup https://emanuelduss.ch/2018/12/advent-calendar-of-advanced-c...
OverTheWire Advent Bonanza 2018 https://advent2018.overthewire.org writeup https://ctftime.org/event/721/tasks
35C3 https://archive.aachen.ccc.de/35c3ctf.ccc.ac/challenges/inde... writeup https://ctftime.org/event/718/tasks
HITB-XCTF Dubai CTF 2018 https://ctftime.org/event/720