- play.kaf.sh
- utc-ctf.club
- wtftime
- justctf
- xmasctf
- watevrctf
- tuctf.com
- ctf.ritsec.club
- nctf.vulnerable.kr
- hack.lu
- seccon.jp
- cryptixctf.com
- rootersctf.in
- ctf2019.syskron-security.com
- picoctf-2019
- sect-ctf
- nactf.com
- ctf.csaw.io
- affinityctf
- twctf
- pase.ca
- hackcon.online
- ctf.sec.army
- ctf.redpwn.net
- gctf-2019
- gctf-2018
Capturing flags for self-education in information security since July 2019.
0xf4b1 on ctftime.org