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Introduction
Bug bounty hunting isn’t about luck—it’s about systematic reconnaissance (Recon). A well-structured Recon process can uncover hidden vulnerabilities, leading to lucrative bounties. In this guide, we break down a professional bug hunter’s workflow, including key tools, commands, and methodologies to maximize your findings.
Learning Objectives
- Master subdomain enumeration techniques
- Validate active hosts efficiently
- Identify original IPs for bypass testing
- Extract and analyze URLs for vulnerabilities
- Automate scanning with Nuclei for critical flaws
You Should Know
1. Subdomain Enumeration: The Foundation of Recon
Subdomain discovery is the first step in bug bounty hunting. Below are verified commands to gather subdomains:
Tools & Commands:
subfinder -d example.com -silent --all | anew Subs.txt assetfinder --subs-only example.com | anew Subs.txt echo "example.com" | alterx -silent | anew Subs.txt bash submax.sh -d example.com > Subs.txt python3 getSubs.py example.com > Subs.txt subfinder -dL Subs.txt -silent --all | anew Sub2.txt
Step-by-Step Explanation:
- Subfinder: Discovers subdomains using multiple sources (DNS, search engines, APIs).
2. Assetfinder: Focuses on subdomains only, reducing noise.
3. Alterx: Generates permutations for subdomain brute-forcing.
- Submax.sh & getSubs.py: Custom scripts for deeper enumeration.
5. Anew: Filters duplicates, ensuring clean output.
Result: 11,741 unique subdomains.
2. Validating Active Hosts with HTTPX
Not all subdomains are live. Filter active ones using:
Command:
cat ALLSUBS.txt | httpx -silent | anew 200Subs.txt
Explanation:
- HTTPX: Fast HTTP probing tool.
- Silent mode: Removes unnecessary logs.
- Anew: Appends only new results.
Result: 460 active hosts.
- Finding the Original IP for Bypass Testing
Many sites hide behind CDNs. Shodan helps uncover the real IP:
Steps:
1. Search `hostname:example.com` in Shodan.
2. Analyze historical IP data.
- Verify with
curl -v http://<IP> -H "Host: example.com".
Use Case: Bypassing IP-based restrictions.
- URL Collection & Analysis for Hidden Endpoints
Extracting URLs from archives and crawlers exposes hidden vulnerabilities.
Commands:
gau example.com | anew URLs.txt gauplus --subs example.com | anew URLs.txt waymore -d example.com -o URLs gospider -s example.com -o URLs waybackurls example.com | anew URLs.txt katana -u example.com -o URLs.txt
Filtering Live URLs:
cat URLs.txt | httpx -silent -status-code | grep "200" | anew LiveURLs.txt
Result: 29,382 live URLs after filtering.
5. Automated Vulnerability Scanning with Nuclei
Once Recon is complete, automate flaw detection:
Command:
nuclei -l LiveURLs.txt -t ~/nuclei-templates/ -o Findings.txt
Explanation:
- Nuclei: Fast, customizable vulnerability scanner.
- Templates: Pre-defined checks for CVEs, misconfigurations, and bugs.
Pro Tip: Use custom templates (e.g., from coffinxp/nuclei-templates).
What Undercode Say
- Key Takeaway 1: Recon is 80% of bug bounty success—automation and persistence win.
- Key Takeaway 2: Original IP discovery can lead to critical bypasses (Cloudflare, WAF, etc.).
Analysis:
A structured Recon process separates successful hunters from random testers. The right tools (Subfinder, HTTPX, Gau, Nuclei) streamline the workflow, while manual verification ensures depth. Future bug bounty programs will likely enforce stricter rate limits, making stealthy, efficient Recon even more vital.
Prediction
As companies improve defenses, Recon automation will dominate bug bounty strategies. Expect AI-driven tools (like AI-assisted subdomain generation) to emerge, making manual checks obsolete. Hunters who master advanced Recon will stay ahead.
Ready to start? Grab the Bug Bounty Bootcamp Ebook for a structured approach to your first $1,000 bounty! 🚀
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IT/Security Reporter URL:
Reported By: Augusto Gaieta – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
