A CTF event is usually timed, and the points are totaled once the time has expired. The winning player/team will be the one that solved the most challenges, and thus, secured the highest score.
- Crackmes - A place where you can download crackmes to improve your reverse engineering skills.
- Cryptohack - A fun free platform for learning modern cryptography.
- CTF Challenge - Collection of 12 vulnerable web applications, each one has its own realistic infrastructure built over several subdomains containing vulnerabilities.
- CTFLearn - Learn cybersecurity the most beginner-friendly way to get into hacking.
- CTF Time - CTF Time is a useful site for teams to organize their participation in CTFs and assemble Teams. The site shows CTF Rankings over time for a team.
- DomGoat - DOM security learning platform
- Hack The Box - Massive online cyber security training platform, allowing individuals, companies, universities and all kinds of organizations around the world to level up their hacking skills.
- Nightmare - Nightmare is an intro to binary exploitation / reverse engineering course based around ctf challenges.
- Offensive Security - Practice your pentesting skills in a standalone, private lab environment within Offensive Security’s Proving Grounds
- pwnable.tw - Pwnable.tw is a wargame site for hackers to test and expand their binary exploiting skills.
- pwnable.kr - A non-commercial wargame site which provides various pwn challenges regarding system exploitation.
- pwnable.xyz - Beginner tailored CTF challenges.
- ringzer0ctf - Ringzero CTF Challenges
- ROP Emporium - Learn return-oriented programming through a series of challenges.
- Roppers Academy - Learn the fundamentals of Computing Fundamentals through Return Oriented Programming.
- Try Hack Me (King of the Hill) - Making it easier to break into security, all through your browser.
- VulnHub - Provide materials that allows anyone to gain practical 'hands-on' experience in digital security.
- Hack-a-Sat - United States Air Force and United States Space Force jointly presents Hack-A-Sat.