ctf101.org

What It Is

CTF101 is an online handbook for beginners getting into Capture The Flag cybersecurity competitions. The site states that it is written and maintained by NYU OSIRIS Lab in collaboration with CTFd. It is not a live or recorded course in the traditional sense; it is closer to a structured knowledge base designed to help learners understand the basic methods, techniques, and tools needed to participate in CTFs.

Core Content and Delivery Format

Based on the table of contents, CTF101 covers many common CTF categories: forensics, file formats, metadata, steganography, disk and memory forensics, Wireshark and packet capture, XOR/hashing/classical cryptography/RSA, SQL injection, command injection, directory traversal, CSRF, XSS, SSRF, PHP template injection, as well as reverse engineering, C, debuggers, decompilers, the stack, GOT, format strings, ROP, buffer overflows, NX, ASLR, Canary, RELRO, and heap exploitation. The format is English online documentation. There is no indication of live classes, recorded lessons, 1-on-1 instruction, assignment grading, or interactive Q&A.

Pricing and Certificates

The site clearly states that the project is open source and uses the MIT Open Source License. There is no mention of course fees, subscriptions, memberships, or paid unlockable content, so the learning materials themselves can be considered free. As for certification, the page does not provide information about completion certificates, exam-based credentials, or professional certificates, so it is not suitable for users whose main goal is earning a certificate.

Pros and Cons

Its strengths are that it is free, open source, clearly structured, and backed by NYU lab and CTFd community involvement. It also recommends practical tools such as Ghidra, Binary Ninja, Pwndbg, WinDbg, Burp Suite, sqlmap, Chrome, Wireshark, VMware, VirtualBox, Python, pwntools, and CyberChef, and explains the basic use of netcat and ConEmu for connecting to service-based challenges. Its limitations are that the content is more of a handbook index and introductory reference; it lacks Chinese-language support, a built-in practice environment, learning progress management, project feedback, and a closed-loop system for structured training.

Who It’s For and Access from China

CTF101 is suitable for CTF beginners, newcomers to cybersecurity competitions, and students who want to quickly build a knowledge map and toolchain. Learners who already have some foundation and need intensive hands-on labs or mentor feedback may still want to combine it with resources such as picoCTF, OverTheWire, PortSwigger Web Security Academy, Hack The Box Academy, and TryHackMe. Access from China cannot be confirmed based only on the site content; network connectivity, GitHub-related contribution links, and downloads for some external tools may depend on the actual user environment. Since the materials are free, the page does not discuss payment methods.