> web2-recon

Web2 recon pipeline — subdomain enumeration (subfinder, Chaos API, assetfinder), live host discovery (dnsx, httpx), URL crawling (katana, waybackurls, gau), directory fuzzing (ffuf), JS analysis (LinkFinder, SecretFinder), continuous monitoring (new subdomain alerts, JS change detection, GitHub commit watch). Use when starting recon on any web2 target or when asked about asset discovery, subdomain enum, or attack surface mapping.

fetch
$curl "https://skillshub.wtf/shuvonsec/claude-bug-bounty/web2-recon?format=md"
SKILL.mdweb2-recon

WEB2 RECON PIPELINE

Full asset discovery from nothing to a prioritized URL list ready for hunting.


SETUP (one-time)

# 1. Set your Chaos API key (get free key at chaos.projectdiscovery.io)
export CHAOS_API_KEY="your-key-here"
# Add to ~/.zshrc or ~/.bashrc for persistence:
echo 'export CHAOS_API_KEY="your-key-here"' >> ~/.zshrc

# 2. Update nuclei templates (run weekly)
nuclei -update-templates

# 3. Configure subfinder with API keys for more sources
mkdir -p ~/.config/subfinder
cat > ~/.config/subfinder/config.yaml << 'EOF'
# Get free keys at: virustotal.com, securitytrails.com, censys.io, shodan.io
virustotal: [YOUR_VT_KEY]
securitytrails: [YOUR_ST_KEY]
censys_apiid: YOUR_CENSYS_ID
censys_secret: YOUR_CENSYS_SECRET
shodan: [YOUR_SHODAN_KEY]
EOF

# 4. Verify all tools installed
which subfinder httpx dnsx nuclei katana waybackurls gau dalfox ffuf anew gf interactsh-client

THE 5-MINUTE RULE

If a target shows nothing interesting after 5 minutes of recon, move on. Don't burn hours on dead surface.

5-minute kill signals:

  • All subdomains return 403 or static marketing pages
  • No API endpoints visible in URLs
  • No JavaScript bundles with interesting endpoint paths
  • nuclei returns 0 medium/high findings
  • No forms, no authentication, no user data

STANDARD RECON PIPELINE

Pre-Hunt: Always Run First

TARGET="target.com"

# Step 0: Passive — crt.sh certificate transparency (no API key needed)
curl -s "https://crt.sh/?q=%.${TARGET}&output=json" \
  | jq -r '.[].name_value' \
  | sed 's/\*\.//g' \
  | sort -u > /tmp/subs.txt
echo "[+] crt.sh: $(wc -l < /tmp/subs.txt) subdomains"

# Step 1: Chaos API (ProjectDiscovery — most comprehensive source)
curl -s "https://dns.projectdiscovery.io/dns/$TARGET/subdomains" \
  -H "Authorization: $CHAOS_API_KEY" \
  | jq -r '.[]' >> /tmp/subs.txt

echo "[+] Chaos returned $(wc -l < /tmp/subs.txt) subdomains"

# Step 2: subfinder (passive multi-source)
subfinder -d $TARGET -silent | anew /tmp/subs.txt
assetfinder --subs-only $TARGET | anew /tmp/subs.txt

echo "[+] Total subdomains after all sources: $(wc -l < /tmp/subs.txt)"

# Step 3: DNS resolution + live host check
cat /tmp/subs.txt | dnsx -silent | httpx -silent -status-code -title -tech-detect | tee /tmp/live.txt

echo "[+] Live hosts: $(wc -l < /tmp/live.txt)"

# Step 4: URL crawl
cat /tmp/live.txt | awk '{print $1}' | katana -d 3 -jc -kf all -silent | anew /tmp/urls.txt

# Step 5: Historical URLs
echo $TARGET | waybackurls | anew /tmp/urls.txt
gau $TARGET --subs | anew /tmp/urls.txt

echo "[+] Total URLs: $(wc -l < /tmp/urls.txt)"

# Step 6: Nuclei scan
nuclei -l /tmp/live.txt -t ~/nuclei-templates/ -severity critical,high,medium -o /tmp/nuclei.txt

Output to Organized Directory

TARGET="target.com"
RECON_DIR="recon/$TARGET"
mkdir -p $RECON_DIR

# All outputs go here:
/tmp/subs.txt         → $RECON_DIR/subdomains.txt
/tmp/live.txt         → $RECON_DIR/live-hosts.txt
/tmp/urls.txt         → $RECON_DIR/urls.txt
/tmp/nuclei.txt       → $RECON_DIR/nuclei.txt

ATTACK SURFACE TRIAGE

Find Interesting Targets in URL List

# Parameters worth testing
cat /tmp/urls.txt | grep -E "[?&](id|user|file|path|url|redirect|next|src|token|key|api_key)=" | tee /tmp/interesting-params.txt

# API endpoints
cat /tmp/urls.txt | grep -E "/api/|/v1/|/v2/|/v3/|/graphql|/rest/|/gql" | tee /tmp/api-endpoints.txt

# File upload endpoints
cat /tmp/urls.txt | grep -E "upload|file|attachment|document|image|avatar|photo|media" | tee /tmp/uploads.txt

# Admin/internal paths
cat /tmp/urls.txt | grep -E "/admin|/internal|/debug|/test|/staging|/dev|/management|/console" | tee /tmp/admin-paths.txt

# Authentication endpoints
cat /tmp/urls.txt | grep -E "/oauth|/login|/auth|/sso|/saml|/oidc|/callback|/token" | tee /tmp/auth-paths.txt

gf Patterns (Quick Classification)

# Install gf patterns: https://github.com/tomnomnom/gf
cat /tmp/urls.txt | gf xss | tee /tmp/xss-candidates.txt
cat /tmp/urls.txt | gf ssrf | tee /tmp/ssrf-candidates.txt
cat /tmp/urls.txt | gf idor | tee /tmp/idor-candidates.txt
cat /tmp/urls.txt | gf sqli | tee /tmp/sqli-candidates.txt
cat /tmp/urls.txt | gf redirect | tee /tmp/redirect-candidates.txt
cat /tmp/urls.txt | gf lfi | tee /tmp/lfi-candidates.txt
cat /tmp/urls.txt | gf rce | tee /tmp/rce-candidates.txt

JS ANALYSIS

SecretFinder (API keys, tokens in JS bundles)

# Activate venv
source ~/tools/SecretFinder/.venv/bin/activate

# Scan a single JS file
python3 ~/tools/SecretFinder/SecretFinder.py -i "https://target.com/static/js/main.js" -o cli

# Scan all JS URLs found in recon
cat /tmp/urls.txt | grep "\.js$" | head -50 | while read url; do
  echo "=== $url ==="
  python3 ~/tools/SecretFinder/SecretFinder.py -i "$url" -o cli 2>/dev/null
done

deactivate

LinkFinder (Endpoints hidden in JS)

source ~/tools/LinkFinder/.venv/bin/activate

# Single JS file
python3 ~/tools/LinkFinder/linkfinder.py -i "https://target.com/app.js" -o cli

# All pages (crawls JS from HTML)
python3 ~/tools/LinkFinder/linkfinder.py -i "https://target.com" -d -o cli

deactivate

DIRECTORY FUZZING

ffuf — Standard Fuzzing

# Directory discovery on a live host
ffuf -u "https://target.com/FUZZ" \
     -w ~/wordlists/common.txt \
     -mc 200,201,204,301,302,307,401,403 \
     -ac \
     -t 40 \
     -o /tmp/ffuf-dirs.json

# API endpoint discovery
ffuf -u "https://target.com/api/FUZZ" \
     -w ~/wordlists/api-endpoints.txt \
     -mc 200,201,204,301,302 \
     -ac \
     -t 20

# IDOR fuzzing with authenticated request
# Create req.txt with Authorization: Bearer TOKEN
ffuf -request /tmp/req.txt \
     -request-proto https \
     -w <(seq 1 10000) \
     -fc 404 \
     -ac \
     -t 10

TARGET SCORING — GO / NO-GO

Score before spending time. Skip if score < 4.

CriterionPoints
Max bounty >= $5K+2
Large user base (>100K) or handles money+2
Program launched < 60 days ago+2
Complex features: API, OAuth, file upload, GraphQL+1
Recent code/feature changes (GitHub, changelog)+1
Private program (less competition)+1
Tech stack you know+1
Source code available+1
Prior disclosed reports to study+1

< 4: Skip 4-5: Only if nothing better available 6-8: Good — spend 1-3 days >= 9: Excellent — spend up to 1 week

Pre-Dive Hard Kill Signals

  1. Max bounty < $500 → not worth your time
  2. All recent reports are N/A or duplicate → hunters saturated it
  3. Scope is only a static marketing page → no attack surface
  4. Company < 5 employees with no revenue → won't pay
  5. Explicitly excludes your planned bug class in rules

TECH STACK DETECTION (2 min)

# Response headers reveal backend
curl -sI https://target.com | grep -iE "server|x-powered-by|x-aspnet|x-runtime|x-generator"

# Common signals:
# Server: nginx + X-Powered-By: PHP/7.4 → PHP backend
# Server: gunicorn OR X-Powered-By: Express → Python/Node.js
# X-Powered-By: ASP.NET → .NET
# Server: Apache Tomcat → Java
# X-Runtime: Ruby → Ruby on Rails

# Framework from JS bundle paths:
# /_next/static/ → Next.js
# /static/js/main.chunk.js → CRA (React)
# /packs/ → Ruby on Rails + Webpacker
# /__nuxt/ → Nuxt.js (Vue)

Stack → Primary Bug Class Map

StackHunt FirstHunt Second
Ruby on RailsMass assignmentIDOR (:id routes)
DjangoIDOR (ModelViewSet, no object perms)SSTI (mark_safe)
FlaskSSTI (render_template_string)SSRF (requests lib)
LaravelMass assignment ($fillable)IDOR (Eloquent, no ownership)
Express (Node.js)Prototype pollutionPath traversal
Spring BootActuator endpoints (/actuator/env)SSTI (Thymeleaf)
ASP.NETViewState deserializationOpen redirect (ReturnUrl)
Next.jsSSRF via Server ActionsOpen redirect via redirect()
GraphQLIntrospection → auth bypass on mutationsIDOR via node(id:)
WordPressPlugin SQLiREST API auth bypass

CONTINUOUS MONITORING SETUP

Set up once per target. Alerts you before other hunters.

New Subdomain Alerts (daily cron)

#!/bin/bash
TARGET="target.com"
KNOWN="/tmp/$TARGET-subs-known.txt"

subfinder -d $TARGET -silent > /tmp/$TARGET-subs-fresh.txt
curl -s "https://dns.projectdiscovery.io/dns/$TARGET/subdomains" \
  -H "Authorization: $CHAOS_API_KEY" \
  | jq -r '.[]' >> /tmp/$TARGET-subs-fresh.txt

# Diff against known
NEW=$(comm -23 <(sort /tmp/$TARGET-subs-fresh.txt) <(sort $KNOWN 2>/dev/null))

if [ -n "$NEW" ]; then
  echo "NEW SUBDOMAINS: $NEW"
  echo "$NEW" >> $KNOWN
fi

# Schedule: crontab -e → 0 8 * * * /bin/bash ~/monitors/subs-watch.sh

GitHub Commit Watch

#!/bin/bash
REPO="TargetOrg/target-app"
LAST_SHA="/tmp/$REPO-last-sha.txt"

CURRENT=$(curl -s "https://api.github.com/repos/$REPO/commits?per_page=1" | jq -r '.[0].sha')
KNOWN=$(cat $LAST_SHA 2>/dev/null)

if [ "$CURRENT" != "$KNOWN" ]; then
  echo "New commit on $REPO: $CURRENT"
  echo $CURRENT > $LAST_SHA
  # Get changed files
  curl -s "https://api.github.com/repos/$REPO/commits/$CURRENT" \
    | jq -r '.files[].filename' | grep -E "auth|middleware|route|permission|role|admin"
fi

# Schedule: */30 * * * * /bin/bash ~/monitors/github-watch.sh

PORT SCANNING (often skipped — don't skip)

# naabu — fast port scanner from ProjectDiscovery
# Finds non-standard ports: 8080, 8443, 3000, 8888, 9000, etc.
cat /tmp/live.txt | awk '{print $1}' | naabu -port 80,443,8080,8443,3000,4000,5000,8000,8888,9000,9090,9200,6379 -silent | tee /tmp/open-ports.txt

# Why this matters: admin panels, debug services, internal APIs often run on alt ports
# Example wins: :8080/actuator/env (Spring Boot), :9200/_cat/indices (Elasticsearch), :6379 (Redis)

SECRET SCANNING IN JS BUNDLES

# trufflehog — high-signal secret detection with entropy analysis
# Scans JS files and git repos
pip install trufflehog3 2>/dev/null || true
trufflehog filesystem --only-verified recon/$TARGET/ 2>/dev/null

# SecretFinder — manual JS bundle scan (already in tools/)
source ~/tools/SecretFinder/.venv/bin/activate
cat /tmp/urls.txt | grep "\.js$" | head -100 | while read url; do
  python3 ~/tools/SecretFinder/SecretFinder.py -i "$url" -o cli 2>/dev/null
done
deactivate

# Quick grep for common patterns in downloaded JS
wget -q -r -l 1 -A "*.js" -P /tmp/js-files/ "https://$TARGET" 2>/dev/null
grep -rn "api_key\|apiKey\|client_secret\|access_token\|private_key\|AWS_SECRET\|AKIA" /tmp/js-files/ 2>/dev/null

GITHUB DORKING FOR TARGET

# Search GitHub for hardcoded secrets before hunting the app
TARGET_ORG="TargetOrgName"  # Check their GitHub org

# Useful dorks (search on github.com):
# org:TARGET_ORG password
# org:TARGET_ORG api_key
# org:TARGET_ORG "Authorization: Bearer"
# org:TARGET_ORG .env
# org:TARGET_ORG "BEGIN RSA PRIVATE KEY"

# CLI with gh (GitHub CLI):
gh search code "api_key" --owner "$TARGET_ORG" --json path,repository 2>/dev/null | jq '.'
gh search code "password" --owner "$TARGET_ORG" --json path,repository 2>/dev/null | head -20

# GitDorker (if installed):
python3 ~/tools/GitDorker/GitDorker.py -t GITHUB_TOKEN -d ~/tools/GitDorker/Dorks/alldorksv3 -q "$TARGET" -org

30-MINUTE RECON PROTOCOL

Minutes 0-5: Read Program Page

Note:
- ALL in-scope assets (every domain listed)
- Out-of-scope list (read carefully — common trap)
- Safe harbor statement
- Impact types accepted (some exclude "low")
- Average bounty amount (signals program generosity)

Minutes 5-15: Asset Discovery

Run the standard pipeline above. Focus on live.txt output.

Minutes 15-25: Surface Map

Run gf patterns and the interesting-params grep above.

Minutes 25-30: Manual Exploration

Open Burp Suite. Browse the app with proxy on:

  1. Register an account
  2. Perform main user actions (create/read/update/delete resources)
  3. Note all API calls in Burp history
  4. Look for endpoints not in your URL list

After 30 min: Prioritize

Priority 1: API endpoints with ID parameters → IDOR candidates
Priority 2: File upload features → XSS/RCE candidates
Priority 3: OAuth/SSO flows → auth bypass candidates
Priority 4: Search/filter with user input → SQLi/SSRF/SSTI candidates
Priority 5: Admin/debug endpoints → auth bypass candidates

> related_skills --same-repo

> web3-audit

Smart contract security audit — 10 DeFi bug classes (accounting desync, access control, incomplete path, off-by-one, oracle, ERC4626, reentrancy, flash loan, signature replay, proxy), pre-dive kill signals (TVL < $500K etc), Foundry PoC template, grep patterns for each class, and real Immunefi paid examples. Use for any Solidity/Rust contract audit or when deciding whether a DeFi target is worth hunting.

> web2-vuln-classes

Complete reference for 20 web2 bug classes with root causes, detection patterns, bypass tables, exploit techniques, and real paid examples. Covers IDOR, auth bypass, XSS, SSRF (11 IP bypass techniques), SQLi, business logic, race conditions, OAuth/OIDC, file upload (10 bypass techniques), GraphQL, LLM/AI (ASI01-ASI10 agentic framework), API misconfig (mass assignment, JWT attacks, prototype pollution, CORS), ATO taxonomy (9 paths), SSTI (Jinja2/Twig/Freemarker/ERB/Spring), subdomain takeover, cl

> triage-validation

Finding validation before writing any report — 7-Question Gate (all 7 questions), 4 pre-submission gates, always-rejected list, conditionally valid with chain table, CVSS 3.1 quick reference, severity decision guide, report title formula, 60-second pre-submit checklist. Use BEFORE writing any report. One wrong answer = kill the finding and move on. Saves N/A ratio.

> security-arsenal

Security payloads, bypass tables, wordlists, gf pattern names, always-rejected bug list, and conditionally-valid-with-chain table. Use when you need specific payloads for XSS/SSRF/SQLi/XXE/NoSQLi/command injection/SSTI/IDOR/path-traversal/HTTP smuggling/WebSocket/MFA bypass, bypass techniques, or to check if a finding is submittable. Also use when asked about what NOT to submit.

┌ stats

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github stars1.0K
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first seenMar 23, 2026
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┌ repo

shuvonsec/claude-bug-bounty
by shuvonsec
└────────────