Below are some great examples of FREE services to practice your CTF skills.
The “A” tier services
picoGym
Ran by the same folks who run picoCTF, Carnegie Mellon University, it is a collection of all the previous challenges in picoCTF. Honestly a great repository of information and starting point after you get Linux Basics down.
CTFlearn
Another beginner-friendly option side-by-side with picoCTF.
TryHackMe Free Tier
TryHackMe has hundreds of free rooms for you to explore various, you don’t need to waffle about their “premium” tier.
The “B” tier services
RingZer0 CTF
Ran by NorthSec, a good online CTF with a bunch of challenges.
OverTheWire Wargames
You may recognize this from our “Bandit OverTheWire” challenge, but did you know they have more than just basic Linux?
PortSwigger Academy
If you’re going more for how to use BurpSuite, this is hosted by the same company that runs develops it.
The “C” tier services
There is none, because I’m not going to waste your time with “okay” resources.
Google and Reading Writeups
If you ever get stuck during a CTF, you can wait until after the CTF is over and then read writeups of people who did complete the challenges. Writeups act as our cybersecurity professional’s form of note taking our thought processes during CTFs, the successes and failures.
