Practice Labs
Hack The Box
VulnHub
PentesterLab
OWASP Juice Shop Project
http://demo.owasp-juice.shop/#/search
OWASP WebGoat Project
https://www.owasp.org/index.php/Category:OWASP_WebGoat_Project
OWASP Mutillidae II
https://sourceforge.net/projects/mutillidae/
HackThis!!
Hack This Site!
bWAPP
Game of Hacks
Hellbound Hackers
https://www.hellboundhackers.org/
Enigma Group
https://www.hellboundhackers.org/
Root Me
https://www.root-me.org/?lang=en
Try2Hack
Hack-Me Brain Teaser
https://hack.me/103934/brain-teaser.html
Crackmes.one
XSS Polyglot Challenge (v2) – by @filedescriptor
CTFs
Pico CTF
CTF Time
captf.com
This site is primarily the work of @psifertex since he needed a dump site for a variety of CTF material and since many other public sites documenting the art and sport of Hacking Capture the Flag events have come and gone over the years.
SANS Holiday Hack Challenge
https://holidayhackchallenge.com/2018/
Flare
National Cyber League
https://www.nationalcyberleague.org/
OverTheWire – Wargames
http://overthewire.org/warzone/
Hackxor
Fuzzy Land
HECF CTF (CTFd)
http://www.hecfblog.com/2018/08/daily-blog-451-defcon-dfir-ctf-2018.html
In Person
StormCTF
https://stormctf.ninja/ctf/events/infosecon-2018
Books
Trail of Bits
https://trailofbits.github.io/ctf/
Lists
https://github.com/vitalysim/Awesome-Hacking-Resources
http://captf.com/practice-ctf/
https://www.blackroomsec.com/updated-hacking-challenge-site-links/
https://trailofbits.github.io/ctf/intro/find.html
https://www.reddit.com/r/hacking/comments/8yq73n/this_might_be_a_dumb_request_but_does_anyone_know/