Web Application Recon And Enumeration

Web Application Recon & Enumeration

When to Use

• As the FIRST STEP in any bug bounty or web application pentest engagement
• When you need to map the target's complete attack surface
• When discovering subdomains, hidden endpoints, and technologies
• When building a target profile before vulnerability testing

Prerequisites

• Authorized scope and target URLs from bug bounty program
• Burp Suite Professional (or Community) configured with browser proxy
• Familiarity with OWASP Top 10 and common web vulnerability classes
• SecLists wordlists for fuzzing and enumeration

Workflow

Phase 1: Passive Subdomain Enumeration

# subfinder — fast passive subdomain discovery
subfinder -d target.com -all -o subdomains.txt

# amass — comprehensive passive enumeration
amass enum -passive -d target.com -o amass_subs.txt

# assetfinder
assetfinder --subs-only target.com >> subdomains.txt

# Merge and deduplicate
cat subdomains.txt amass_subs.txt | sort -u > all_subs.txt
echo "[+] Total unique subdomains: $(wc -l < all_subs.txt)"

Phase 2: DNS Resolution & HTTP Probing

# Resolve live subdomains
cat all_subs.txt | httpx -silent -status-code -title -tech-detect -o live_hosts.txt

# Check which hosts respond on interesting ports
cat all_subs.txt | httpx -ports 80,443,8080,8443,3000,5000,8000,9090 -silent -o all_ports.txt

# Quick Nmap for service detection
nmap -sV -sC -p 21,22,80,443,3306,5432,8080,8443 -iL live_ips.txt -oA nmap_scan

Phase 3: Technology Fingerprinting

# Wappalyzer-style detection (httpx already does this with -tech-detect)
# Additional: Nuclei technology detection
nuclei -l live_hosts.txt -t technologies/ -o tech_results.txt

# whatweb for detailed fingerprinting
whatweb -i live_hosts.txt --log-brief=whatweb_results.txt

# Check for known CMS
# WordPress: /wp-admin, /wp-content, /xmlrpc.php
# Drupal: /core/CHANGELOG.txt, /user/login
# Joomla: /administrator, /api/index.php

Phase 4: Directory & Content Discovery

# ffuf — fast fuzzer
ffuf -u https://target.com/FUZZ -w /usr/share/seclists/Discovery/Web-Content/raft-large-directories.txt \
  -mc 200,301,302,403 -o ffuf_dirs.json

# API endpoint discovery
ffuf -u https://target.com/api/FUZZ -w /usr/share/seclists/Discovery/Web-Content/api/api-endpoints.txt \
  -mc 200,401,403 -o api_endpoints.json

# Backup file discovery
ffuf -u https://target.com/FUZZ -w /usr/share/seclists/Discovery/Web-Content/raft-large-files.txt \
  -e .bak,.old,.zip,.tar.gz,.sql,.env,.git -mc 200 -o backups.json

Phase 5: Historical Data & JavaScript Analysis

# Wayback Machine URLs
echo "target.com" | waybackurls | sort -u > wayback_urls.txt

# GAU (GetAllUrls)
echo "target.com" | gau --threads 5 | sort -u > gau_urls.txt

# Extract JavaScript files
cat wayback_urls.txt gau_urls.txt | grep "\.js$" | sort -u > js_files.txt

# Analyze JS for endpoints, secrets, API keys
cat js_files.txt | while read url; do
  curl -s "$url" | grep -oP '(api|endpoint|url|secret|key|token|password)\s*[:=]\s*["\x27][^"\x27]+["\x27]'
done > js_secrets.txt

# LinkFinder for endpoint extraction from JavaScript
python3 linkfinder.py -i https://target.com -d -o endpoints.html

Phase 6: Vulnerability Scanning

# Nuclei — fast vulnerability scanner
nuclei -l live_hosts.txt -t cves/ -t exposures/ -t misconfiguration/ \
  -severity critical,high,medium -o nuclei_vulns.txt

# Check for common misconfigurations
nuclei -l live_hosts.txt -t misconfiguration/ -o misconfig.txt

# Check exposed panels and default credentials
nuclei -l live_hosts.txt -t default-logins/ -o default_creds.txt

⚡ OPSEC & Anti-Detection for Bug Bounty

Never get rate-limited or blocked before you find the bug.

• Request Timing: Add 200-500ms jitter between automated requests — never burst
• User-Agent Rotation: Use realistic browser UA strings, not tool defaults
• IP Rotation: Use residential proxies for long engagements, not datacenter IPs
• Session Preservation: Test in authenticated context to avoid WAF triggers on unauthenticated rapid probing
• Avoid Scanner Signatures: Strip nuclei/ffuf/sqlmap markers from requests; triagers check for low-effort automation
• Incremental Fuzzing: Start with 50 requests/minute, increase only after confirming no rate limiting

🌐 Modern Recon Pipeline (8-Phase Cycle — 2026 Standard)

Source: Jason Haddix, NahamSec, and InsiderPHD (Katie Paxton-Fear) methodologies

Phase 1 — ASN Discovery: bgp.he.net → Find all owned IP ranges via ASN Phase 2 — Apex Domain Discovery: tenantdomains.sh → Microsoft tenant correlation Phase 3 — Acquisition Intel: Traxon/Pitchbook → Find M&A targets = fresh attack surface Phase 4 — Cloud SSL Recon: Caduceus/Gungnir → Scan AWS/GCP/Azure IPs for SSL metadata Phase 5 — Port Scanning: ASNmap → Nabu → Nmap cascade for service enumeration Phase 6 — Passive Shodan Dorking: Karma → Pre-identified vulns without sending packets Phase 7 — Subdomain Aggregation: SubFinder + Beebot + Chaos + Amass (parallel, with API keys) Phase 8 — "The One-Liner":

cat apexes.txt | subfinder | httpx -sc -title -cl -web-server -asn -l 15 \
  -ports 80,8080,443,8443,4443,8888 -o output.csv

Premium Intel Sources (Top 1% Use These):

• GitHub CFOR (Cross-Fork Object References) — Find developer personal repos with leaked secrets
• Cisco Umbrella passive DNS — 10-20% more subdomains than public sources
• CT Log monitoring via Gungnir — Real-time new certificate alerts
• Shodan InternetDB API — Instant port+banner data without scanning

🔵 Blue Team Detection

• Asset inventory: Maintain a current inventory of all subdomains and services
• Rate limiting: Detect and block rapid enumeration attempts
• Honeypot subdomains: Create decoy subdomains and alert on access
• DNS monitoring: Alert on subdomain enumeration patterns

Output Format

Reconnaissance Report
======================
Target: target.com
Subdomains: 342 discovered, 187 live
Open Ports: 22(SSH), 80(HTTP), 443(HTTPS), 8080(HTTP-Alt)
Technologies: nginx/1.18, PHP/8.1, WordPress 6.4, MySQL 8.0
CMS: WordPress (outdated plugins detected)
API Endpoints: 45 discovered (/api/v1/*, /api/v2/*)
Sensitive Files: .env exposed, .git directory accessible
JavaScript Secrets: 3 API keys found in JS files

💰 Industry Bounty Payout Statistics (2024-2025)

Key Takeaway: Google alone paid $17.1M in 2025 — a 40% increase YoY. Microsoft paid $16.6M. The industry is paying more, not less. Average critical bounty on HackerOne: $3,700 (2023).

📚 Shared Resources

For cross-cutting methodology applicable to all vulnerability classes, see:

• _shared/references/elite-chaining-strategy.md — Exploit chaining methodology and high-payout chain patterns
• _shared/references/elite-report-writing.md — HackerOne-optimized report writing, CWE quick reference
• _shared/references/real-world-bounties.md — Verified disclosed bounties by vulnerability class

References

• OWASP: Web Security Testing Guide — Information Gathering
• Bug Bounty Methodology: Nahamsec Recon Guide