Step-by-Step Guide to Learn Capture The Flag (CTF)
Step-by-Step Guide to Learn Capture The Flag (CTF)
1. Understand What CTFs Are
CTFs are gamified security competitions with different challenge categories:
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Pwn: Binary exploitation
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Reversing: Reverse engineering binaries
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Web: Web app security (e.g., XSS, SQLi)
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Crypto: Cryptography challenges
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Forensics: File analysis, packet capture, memory dumps
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Misc: Steganography, OSINT, etc.
There are two types of competitions:
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Jeopardy-style (solve isolated challenges for points)
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Attack-Defense-style (teams protect their own systems while attacking others)
2. Set Up Your Practice Environment
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A Linux system (Kali Linux or Ubuntu) is ideal.
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Install essential tools:
pwndbg,radare2,Ghidra,Burp Suite,nmap, etc. -
Use virtual machines (e.g., VirtualBox or VMware) or Docker to safely test.
3. Start Practicing with Beginner-Friendly Platforms
Here are some top platforms to get hands-on experience:
| Platform | Focus | Notes |
|---|---|---|
| picoCTF | Beginner | Created by Carnegie Mellon |
| HackTheBox | Realistic | Labs and CTFs |
| TryHackMe | Guided | Very beginner-friendly |
| CTFlearn | Mixed | Good beginner CTFs |
| OverTheWire | Linux, Pwn | Bandit (great start), Narnia |
4. Learn the Basics of Key Topics
📂 Web Security
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Learn OWASP Top 10
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Try Burp Suite, inspect requests/responses
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Practice SQLi, XSS, CSRF on labs like PortSwigger
🔐 Cryptography
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Understand basic ciphers: Caesar, XOR, RSA
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Learn number theory, modular arithmetic
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Practice on CryptoHack or Cryptopals
🔎 Reverse Engineering
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Learn how to read assembly (x86, ARM)
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Tools: Ghidra, IDA Free, radare2
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Start with reversing crackmes (see Crackmes.one)
💥 Pwn (Binary Exploitation)
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Understand buffer overflows, stack layout
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Practice with
pwntools, GDB,pwndbg -
Start with
Protostarorpwnable.kr
🕵️ Forensics
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Use tools like Wireshark, binwalk, strings, steghide
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Practice extracting hidden data from files
5. Join a CTF Team or Community
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Reddit: r/CTFs, r/netsec
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Discord servers (e.g., CTFTime's, picoCTF's)
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Join or form a team on CTFTime
6. Participate in Real CTFs
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CTFTime.org lists upcoming competitions.
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Join beginner-friendly events like:
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picoCTF
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Google CTF (Beginners)
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CSAW CTF
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TJCTF
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7. Read Writeups and Post Yours
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Analyze writeups on:
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CTFTime
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GitHub repos (search
CTF writeups) -
ctfs.github.io
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After solving a challenge, write your own walkthrough. Teaching is learning.
📚 Recommended Resources
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Books:
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The Web Application Hacker’s Handbook
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Practical Binary Analysis
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Hacking: The Art of Exploitation
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Courses:
🔁 Mindset Tips
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Don't rush. CTFs are hard at first—expect to Google a lot.
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Collaborate and ask for hints in communities.
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Treat every unsolved challenge as a learning opportunity.
🛠️ Phase 1: Leverage Your Python Skills
🔸 Automate Challenges
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Learn pwntools for binary exploitation scripts:
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Use Python for automating:
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Brute force logic
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Encoding/decoding
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Data extraction (e.g., regex on packet dumps)
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🔸 Practice Challenges
Start with beginner web, crypto, and misc challenges where Python can help:
🧠 Phase 2: Deepen Exploitation and Reversing Skills
🔹 Binary Exploitation (Pwn)
Use your Linux knowledge to explore:
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Buffer overflows, format strings, shellcode
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Tools:
gdb,pwndbg,pwntools -
Start with:
🔹 Reverse Engineering
Python helps with automation in:
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Deobfuscation scripts
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Binary patching
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Use tools like:
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Ghidra (static)
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radare2 (dynamic + scripting)
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Practice with:
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picoCTF reversing challenges
🔐 Phase 3: Crypto and Web Exploits
🔸 Crypto
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Learn modular arithmetic, XOR, RSA basics
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Use Python to implement decryption logic
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Practice on:
🔸 Web Security
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Practice with Burp Suite
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Use Python +
requestsorSeleniumto automate attacks -
Try labs at:
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picoCTF Web category
🔁 Phase 4: Practice and Join Events
🔹 Daily/Weekly Practice
🔹 Join CTF Events
Track beginner-friendly CTFs at CTFTime:
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picoCTF (Mar-Apr)
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TJCTF
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UMass CTF
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Google CTF (Beginner)
✍️ Phase 5: Document & Share
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Create a GitHub repo or blog for your writeups
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Read other people's writeups on CTFTime and GitHub
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Explain solutions in Python when possible
🗓️ Week 1: Foundation + Easy Wins
🎯 Goals:
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Understand CTF structure and categories
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Solve beginner-level Web, Crypto, and Misc challenges
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Set up your tools
✅ Tasks:
| Task | Resource/Tool |
|---|---|
| Sign up: picoCTF, CTFlearn | - |
| Watch: LiveOverflow – Intro to CTF | YouTube |
| Install: Ghidra, GDB, pwntools, Burp Suite, Wireshark | Terminal |
| Solve: 10+ beginner challenges (Web/Crypto/Misc) on picoCTF | picoCTF |
| Script basic CTF utilities (Caesar/XOR, base64 decode, etc.) | Python |
🗓️ Week 2: Binary Basics & Reversing
🎯 Goals:
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Understand binary formats and memory layout
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Get comfortable with reverse engineering tools
✅ Tasks:
| Task | Resource/Tool |
|---|---|
| Complete: Bandit levels 0–10 | OverTheWire |
| Read: Intro to Assembly (x86) | Skilldrick |
| Watch: LiveOverflow Reverse Engineering Playlist | YouTube |
| Practice: 3+ reversing challenges on CTFlearn or picoCTF | - |
Tool time: Run strings, objdump, gdb, pwndbg on simple ELF | Terminal |
🗓️ Week 3: Binary Exploitation & Scripting
🎯 Goals:
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Write Python exploits with pwntools
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Understand common vulnerabilities (BOF, FSB)
✅ Tasks:
| Task | Resource/Tool |
|---|---|
| Read: Buffer Overflows with pwntools | GitHub |
| Practice: Protostar stack0–4 | OverTheWire Protostar |
| Write: Python scripts to automate simple buffer overflows | pwntools |
| Try: 2-3 challenges from pwnable.kr | - |
| Optional: Solve 1 RE or pwn challenge on HackTheBox | HackTheBox |
🗓️ Week 4: Crypto & Real CTF Simulation
🎯 Goals:
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Practice realistic crypto/web challenges
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Simulate a real CTF experience (timed, mixed challenges)
✅ Tasks:
| Task | Resource/Tool |
|---|---|
| Practice: 5+ beginner crypto challenges | CryptoHack |
Try: Stego, forensics (use binwalk, steghide, zsteg) | Terminal |
| Participate in a CTF (or replay an old one from CTFTime) | CTFTime |
| Write: Solutions & post them on GitHub | Markdown |
| Review: Other writeups of challenges you solved | GitHub/CTFTime |
🧠 Ongoing Habits:
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Join CTF Discords (e.g., picoCTF, CTFTime)
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Follow CTF Twitter/X tags:
#ctf,#infosec
CTF Learning Plan
✅ Top Recommendation (Best Step-by-Step Starter)
📘 “The Hacker Playbook 3: Practical Guide To Penetration Testing” – Peter Kim
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Why it's great:
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Step-by-step labs from recon to exploitation.
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Covers CTF-style thinking: buffer overflows, web hacking, privilege escalation.
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Integrates tools and scripting (Python, Bash).
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Perfect bridge between beginner and intermediate CTF skills.
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Bonus: You'll learn how to think like a hacker—not just solve puzzles.
🥈 Other Great Books by Category
🛠️ General CTF Skills & Challenges
📘 “Real-World Bug Hunting” – Peter Yaworski
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Focuses on web vulnerabilities with real-world case studies.
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Good for practicing web CTF categories.
🔍 Binary Exploitation & Reversing
📘 “Hacking: The Art of Exploitation (2nd Ed)” – Jon Erickson
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Teaches C programming, assembly, and memory hacking from scratch.
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Great for understanding what’s going on under the hood.
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Comes with a LiveCD environment for safe experimentation.
🔒 Cryptography for CTF
📘 “Serious Cryptography” – Jean-Philippe Aumasson
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A more formal intro, but excellent for building solid crypto intuition.
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Pair with Cryptopals for hands-on learning.
👨💻 Reverse Engineering Focus
📘 “Practical Reverse Engineering” – Bruce Dang et al.
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Deep dive into reverse engineering Windows/Linux binaries.
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Excellent if you're planning to tackle high-level RE challenges.
🧠 Suggested Book Progression for You
| Phase | Book |
|---|---|
| Start here | ✅ The Hacker Playbook 3 |
| Learn systems deeper | Hacking: The Art of Exploitation |
| Web/crypto focused challenges | Real-World Bug Hunting, Serious Cryptography |
| Advanced reversing | Practical Reverse Engineering |
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