| name | web2-recon |
| description | 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. |
WEB2 RECON PIPELINE
Full asset discovery from nothing to a prioritized URL list ready for hunting.
SETUP (one-time)
export CHAOS_API_KEY="your-key-here"
echo 'export CHAOS_API_KEY="your-key-here"' >> ~/.zshrc
nuclei -update-templates
mkdir -p ~/.config/subfinder
cat > ~/.config/subfinder/config.yaml << 'EOF'
virustotal: [YOUR_VT_KEY]
securitytrails: [YOUR_ST_KEY]
censys_apiid: YOUR_CENSYS_ID
censys_secret: YOUR_CENSYS_SECRET
shodan: [YOUR_SHODAN_KEY]
EOF
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"
curl -s "https://crt.sh/?q=%.${TARGET}&output=json" \
| jq -r '.[].name_value' \
| sed 's/\*\.//g' \
| sort -u > /tmp/subs.txt
echo "[+] crt.sh: $(wc -l < /tmp/subs.txt) subdomains"
curl -s "https://dns.projectdiscovery.io/dns/$TARGET/subdomains" \
-H "Authorization: $CHAOS_API_KEY" \
| jq -r '.[]' >> /tmp/subs.txt
echo "[+] Chaos returned $(wc -l < /tmp/subs.txt) subdomains"
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)"
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)"
cat /tmp/live.txt | awk '{print $1}' | katana -d 3 -jc -kf all -silent | anew /tmp/urls.txt
echo $TARGET | waybackurls | anew /tmp/urls.txt
gau $TARGET --subs | anew /tmp/urls.txt
echo "[+] Total URLs: $(wc -l < /tmp/urls.txt)"
nuclei -l /tmp/live.txt -t ~/nuclei-templates/ -severity critical,high,medium -o /tmp/nuclei.txt
Output to Organized Directory
TARGET="target.com"
RECON_DIR="recon/$TARGET"
mkdir -p $RECON_DIR
/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 → $RECON_DIR/nuclei.txt
ATTACK SURFACE TRIAGE
Find Interesting Targets in URL List
cat /tmp/urls.txt | grep -E "[?&](id|user|file|path|url|redirect|next|src|token|key|api_key)=" | tee /tmp/interesting-params.txt
cat /tmp/urls.txt | grep -E "/api/|/v1/|/v2/|/v3/|/graphql|/rest/|/gql" | tee /tmp/api-endpoints.txt
cat /tmp/urls.txt | grep -E "upload|file|attachment|document|image|avatar|photo|media" | tee /tmp/uploads.txt
cat /tmp/urls.txt | grep -E "/admin|/internal|/debug|/test|/staging|/dev|/management|/console" | tee /tmp/admin-paths.txt
cat /tmp/urls.txt | grep -E "/oauth|/login|/auth|/sso|/saml|/oidc|/callback|/token" | tee /tmp/auth-paths.txt
gf Patterns (Quick Classification)
cat /tmp/urls.txt | gf xss | tee /tmp/xss-candidates.txt
cat /tmp/urls.txt | gf ssrf | tee /tmp/ssrf-candidates.txt
cat /tmp/urls.txt | gf idor | tee /tmp/idor-candidates.txt
cat /tmp/urls.txt | gf sqli | tee /tmp/sqli-candidates.txt
cat /tmp/urls.txt | gf redirect | tee /tmp/redirect-candidates.txt
cat /tmp/urls.txt | gf lfi | tee /tmp/lfi-candidates.txt
cat /tmp/urls.txt | gf rce | tee /tmp/rce-candidates.txt
JS ANALYSIS
SecretFinder (API keys, tokens in JS bundles)
source ~/tools/SecretFinder/.venv/bin/activate
python3 ~/tools/SecretFinder/SecretFinder.py -i "https://target.com/static/js/main.js" -o cli
cat /tmp/urls.txt | grep "\.js$" | 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
python3 ~/tools/LinkFinder/linkfinder.py -i "https://target.com/app.js" -o cli
python3 ~/tools/LinkFinder/linkfinder.py -i "https://target.com" -d -o cli
deactivate
DIRECTORY FUZZING
ffuf — Standard Fuzzing
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
ffuf -u "https://target.com/api/FUZZ" \
-w ~/wordlists/api-endpoints.txt \
-mc 200,201,204,301,302 \
-ac \
-t 20
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.
| Criterion | Points |
|---|
| 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
- Max bounty < $500 → not worth your time
- All recent reports are N/A or duplicate → hunters saturated it
- Scope is only a static marketing page → no attack surface
- Company < 5 employees with no revenue → won't pay
- Explicitly excludes your planned bug class in rules
TECH STACK DETECTION (2 min)
curl -sI https://target.com | grep -iE "server|x-powered-by|x-aspnet|x-runtime|x-generator"
Stack → Primary Bug Class Map
| Stack | Hunt First | Hunt Second |
|---|
| Ruby on Rails | Mass assignment | IDOR (:id routes) |
| Django | IDOR (ModelViewSet, no object perms) | SSTI (mark_safe) |
| Flask | SSTI (render_template_string) | SSRF (requests lib) |
| Laravel | Mass assignment ($fillable) | IDOR (Eloquent, no ownership) |
| Express (Node.js) | Prototype pollution | Path traversal |
| Spring Boot | Actuator endpoints (/actuator/env) | SSTI (Thymeleaf) |
| ASP.NET | ViewState deserialization | Open redirect (ReturnUrl) |
| Next.js | SSRF via Server Actions | Open redirect via redirect() |
| GraphQL | Introspection → auth bypass on mutations | IDOR via node(id:) |
| WordPress | Plugin SQLi | REST 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
NEW=$(comm -23 <(sort /tmp/$TARGET-subs-fresh.txt) <(sort $KNOWN 2>/dev/null))
if [ -n "$NEW" ]; then
echo "NEW SUBDOMAINS: $NEW"
echo "$NEW" >> $KNOWN
fi
GitHub Commit Watch
#!/bin/bash
REPO="TargetOrg/target-app"
LAST_SHA="/tmp/$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 > $LAST_SHA
curl -s "https://api.github.com/repos/$REPO/commits/$CURRENT" \
| jq -r '.files[].filename' | grep -E "auth|middleware|route|permission|role|admin"
fi
PORT SCANNING (often skipped — don't skip)
cat /tmp/live.txt | awk '{print $1}' | naabu -port 80,443,8080,8443,3000,4000,5000,8000,8888,9000,9090,9200,6379 -silent | tee /tmp/open-ports.txt
SECRET SCANNING IN JS BUNDLES
pip install trufflehog3 2>/dev/null || true
trufflehog filesystem --only-verified recon/$TARGET/ 2>/dev/null
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
wget -q -r -l 1 -A "*.js" -P /tmp/js-files/ "https://$TARGET" 2>/dev/null
grep -rn "api_key\|apiKey\|client_secret\|access_token\|private_key\|AWS_SECRET\|AKIA" /tmp/js-files/ 2>/dev/null
GITHUB DORKING FOR TARGET
TARGET_ORG="TargetOrgName"
gh search code "api_key" --owner "$TARGET_ORG" --json path,repository 2>/dev/null | jq '.'
gh search code "password" --owner "$TARGET_ORG" --json path,repository 2>/dev/null | head -20
python3 ~/tools/GitDorker/GitDorker.py -t GITHUB_TOKEN -d ~/tools/GitDorker/Dorks/alldorksv3 -q "$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:
- Register an account
- Perform main user actions (create/read/update/delete resources)
- Note all API calls in Burp history
- 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
Toolchain fallback (when dnsx / httpx crash)
The projectdiscovery Go binaries (dnsx, httpx, naabu) occasionally SIGSEGV on macOS arm64 due to a cgo / system-resolver interaction. The crash signature is identical regardless of install method — both brew install and go install github.com/projectdiscovery/<tool>@latest produce binaries that segfault at the same address. Smoke-test once before relying on them in a real engagement:
dnsx -version
httpx -version
dnsx → dig fallback
while read s; do
ips=$(dig +short +tries=1 +time=3 "$s" \
| grep -E '^[0-9.]+$' \
| paste -sd, -)
[ -n "$ips" ] && echo "$s|$ips"
done < subs.txt
httpx → curl fallback
while read s; do
resp=$(curl -s -L -m 5 -o /tmp/body \
-w "%{http_code}|%{url_effective}|%{header_server}" \
"https://$s")
code=$(echo "$resp" | cut -d'|' -f1)
if [ "$code" != "000" ]; then
title=$(grep -oE '<title[^>]*>[^<]*</title>' /tmp/body | head -1 | sed 's/<[^>]*>//g')
echo "$s|$resp|$title"
fi
done < subs.txt
Trade-off: Serial vs. concurrent. The fallback handles ~24 subdomains in 14 seconds; the same workload on httpx with default 50 threads finishes in 2-3 seconds. For VDP-scale recon (< 100 subdomains) the fallback is fine. For mass recon (1000+) fix the toolchain first.
Verified against HackerOne's own VDP in docs/verification/recon-hackerone-vdp.md.
API Spec / Swagger / OpenAPI Discovery (2024-2026 surface)
API spec endpoints are the single highest-leverage recon target on any modern .NET / Node / Python / Java backend. The spec discloses every endpoint, HTTP methods, parameter names + types + formats, models, validation rules — a complete attack-map in JSON. Default routes are commonly left enabled in production. Add this wordlist to the directory-fuzzing phase (after the standard common.txt pass).
Default discovery path wordlist (paste into swagger-paths.txt)
# NSwag / Swashbuckle (ASP.NET Core)
/swagger
/swagger/
/swagger/index.html
/swagger/ui/index.html
/swagger/v1/swagger.json
/swagger/v2/swagger.json
/swagger/v3/swagger.json
/swagger/docs/v1
/swagger/docs/v2
/swagger-ui
/swagger-ui/
/swagger-ui.html
/swagger-resources
/swagger-resources/configuration/ui
/nswag
/nswag/index.html
/api/swagger
/api/swagger.json
/api/swagger/v1/swagger.json
/api/openapi
/api/openapi.json
/api/v1/swagger.json
/api/v2/swagger.json
/api-docs
/api-docs/swagger.json
# OpenAPI generic
/openapi
/openapi.json
/openapi.yaml
/openapi.yml
/openapi/v1.json
/openapi/v2.json
/openapi/v3.json
/.well-known/openapi.json
# Java / Spring (Springfox / springdoc)
/v2/api-docs
/v3/api-docs
/v3/api-docs.yaml
/v3/api-docs/swagger-config
/swagger-ui/index.html
# Python (FastAPI / Flask-RESTPlus / Connexion / DRF)
/docs
/docs/
/redoc
/redoc/
/openapi.json
/swagger.json
/swagger/?format=openapi
/swagger.yaml
# Express / Node / Hapi
/api-docs
/api-docs.json
/swagger.json
/swagger-stats
/graphql-docs
# GraphQL adjacent (often co-located)
/graphql
/graphiql
/playground
/altair
/voyager
/graphql/console
/graphql-explorer
# ReDoc / RapiDoc / Stoplight / alt UIs
/redoc
/redoc.html
/redoc-ui.html
/rapidoc
/rapidoc.html
/stoplight
/elements
# Misc / dev-leftover
/actuator
/actuator/openapi
/actuator/mappings
/q/openapi
/q/swagger-ui
/docs/swagger.json
/api/v1/docs
/api/v2/docs
/internal/swagger
/admin/swagger
/management/swagger
Integration with the standard pipeline
ffuf -w swagger-paths.txt -u "https://FUZZ.target.com" -mc 200,302 -fs 0 -t 50 -o swagger-hits.json
httpx -l live-hosts.txt -path swagger-paths.txt -mc 200 -mr "swagger|openapi" -json | tee swagger-hits.jsonl
jq '.paths | keys' swagger.json > endpoints.txt
jq '.components.schemas' swagger.json > schemas.json
Why this matters for recon-to-hunting handoff
- Spec → mass IDOR/BOLA —
jq '.paths | keys' swagger.json becomes the input list for Autorize/ffuf per-user testing.
- Spec → mass-assignment payload construction —
components.schemas.UserUpdateDto enumerates isAdmin, emailVerified, tenantId, role.
- Spec → hidden endpoint discovery —
/internal/*, /debug/*, /v0/*, /legacy/* routes documented but never auth-gated.
- Spec → injection-class seeding — every parameter's type + format + enum + max-length means payloads pass validation before reaching the sink. Especially valuable against ASP.NET Core where the model binder rejects malformed input before any controller logic.
Tools
kiterunner — natively ingests OpenAPI spec, generates requests against the API.
sj (Swagger Jacker) — purpose-built for Swagger spec exploitation.
apidetector (brinhosa) — Swagger-UI mass scanner.
XSSwagger (vavkamil) — detects vulnerable Swagger UI versions (CVE-2018-25031 family).
nuclei -t http/exposures/apis/ — built-in templates for default spec paths.
Anti-pattern reminder
A 404/403 on /swagger does NOT mean no spec is exposed. Many .NET projects route the spec under /api/swagger/v1/swagger.json rather than /swagger. Always test the full path list, not just the root.
Full attack-chain analysis is in hunt-api-misconfig → NSwag / Swagger / OpenAPI Spec Exposure.
Related Skills & Chains
offensive-osint — When recon needs concrete probes / wordlists / regexes beyond the basic pipeline. Workflow primitive: this skill produces the URL set; offensive-osint provides the secret regexes, GraphQL/Swagger paths, and identity-fabric probes you apply to that URL set.
osint-methodology — When you need a severity rubric for what you discovered. Workflow primitive: after recon outputs subdomains.txt / live-hosts.txt / urls.txt, score each asset against osint-methodology's findings rubric to decide what gets a finding versus what stays in the asset graph.
hunt-subdomain — When recon surfaces stale CNAMEs / dangling DNS. Workflow primitive: any subdomain in subdomains.txt whose CNAME points to S3 / GitHub Pages / Heroku / Shopify / Azure should auto-route to hunt-subdomain for takeover validation.
security-arsenal — When the URL set is classified by gf and ready for active testing. Workflow primitive: gf xss/ssrf/sqli/idor output names become payload-class queries against security-arsenal's payload library.
bb-methodology — When recon completes and Phase 1 transitions to Phase 2 (Mapping). Workflow primitive: hand the live host + URL set back to bb-methodology Phase 2 for endpoint mapping and Phase 3 vulnerability discovery routing.
Operator Notes (Claude-BugHunter)
Engagement-derived + 2026-specific additions to the vendored foundation.
Wisdom from real authorized engagements + Phase 2 verification across
this repo's 31+ skill-area live tests. The upstream pipeline covers the WHAT;
this layer covers the WHEN-IT-WORKS-vs-WHEN-IT-DOESN'T.
Cross-TLD pivot discipline
Phase 2C's HackerOne VDP recon walked from hackerone.com (24 subdomains) into a sister TLD hacker.one (12 more subdomains found in JS bundle references). Operators who only enumerate *.target.com miss attack surface that the target legitimately operates on a different domain.
Always grep JS bundles for plausible sibling TLDs:
for url in $(cat live-hosts.txt); do
curl -s "$url" | grep -oE 'src="[^"]+\.js"' | sed 's/src="//;s/"//'
done | sort -u > js-urls.txt
for j in $(cat js-urls.txt); do
curl -s "$j" | grep -oE '[a-z0-9.-]+\.(io|app|one|dev|test|cloud|ai|co)' | sort -u
done | sort -u > sibling-tld-candidates.txt
Common sibling-TLD patterns: target.com → target.io / target.app / target.one / target.dev / target.test / target-corp.com / target-cdn.net. Always validate via WHOIS or by checking if the cert chain trusts the same internal CA before treating the sister TLD as in-scope.
Subdomain wordlist priorities by 2026
Top discovery prefixes by hit rate against enterprise VDPs in our 2024-2026 corpus:
mta-sts.* api.* docs.*
dev-* staging-* *-qa
*-stage *-uat events.*
portal.* customer.* partner.*
vendor.* internal-* admin-*
employee-* hr.* jobs.*
sso.* auth.* id.*
Internal-looking subdomains often expose more surface than the marketing site — partner.target.com and vendor-portal.target.com frequently have weaker auth than the main app because they're scoped for "trusted" external users. Always send a probe to the long-tail wordlist after the standard subfinder run completes.
Live-host probe: how to fingerprint stack quickly
curl -sI <host> headers are 80% of the fingerprint:
Server: — apache / nginx / cloudflare / kestrel (= .NET Core) / openresty / envoy
X-Powered-By: — PHP version, ASP.NET version, Express.js
X-Drupal-Cache, X-Generator: Drupal 9 — Drupal
X-Generator: WordPress — WordPress
Via: — CDN chain (1.1 varnish, 1.1 cloudfront)
Set-Cookie: names — JSESSIONID (Java), PHPSESSID (PHP), ASP.NET_SessionId (.NET), connect.sid (Express), laravel_session (Laravel)
JS bundle filename patterns:
/_next/static/ = Next.js
/_nuxt/ = Nuxt
/assets/static/ with hash filenames = Vite
/static/js/main.*.chunk.js = Create React App
runtime.*.js + polyfills.*.js + main.*.js = Angular CLI
The first 10s of recon should yield a stack guess; the rest is targeting. If your fingerprint contradicts itself (Server says nginx, Set-Cookie says ASP.NET) you've found a reverse proxy front-end — note the origin app for later smuggling/cache attacks.
GitHub Pages 404 vs takeover signal
Critical distinction operators get wrong:
- "Page not found · GitHub Pages" with HTTP 404 means the repo EXISTS — NOT a takeover.
- "There isn't a GitHub Pages site here" means the repo was deleted — TAKEOVER candidate.
Same distinction for CloudFront:
- "Error - 404" with
Server: CloudFront = distribution exists, origin returned 404 — NOT a takeover.
- "The request could not be satisfied" with
X-Cache: Error from cloudfront = origin missing entirely — potential takeover.
Phase 2C verified both patterns live. Always check the EXACT response body string before filing a takeover finding — the takeover-scanner tools (subzy, subjack) match on multiple fingerprints and frequently false-positive on the "still owned, just empty" case.
Toolchain fallback
Already covered in this file's Phase 2C addition. Quick reminder: dnsx/httpx may segfault on macOS arm64; the dig+curl fallback works for < 100-host runs in ~14 seconds. Don't burn an hour debugging Go binary panics when the fallback gets you to the same URL set.