Free SKILL.md scraped from GitHub. Clone the repo or copy the file directly into your Claude Code skills directory.
npx versuz@latest install shuvonsec-claude-bug-bounty-skills-bb-methodologygit clone https://github.com/shuvonsec/claude-bug-bounty.gitcp claude-bug-bounty/SKILL.MD ~/.claude/skills/shuvonsec-claude-bug-bounty-skills-bb-methodology/SKILL.md---
name: bb-methodology
description: Use at the START of any bug bounty hunting session, when switching targets, or when feeling lost about what to do next. Master orchestrator that combines the 5-phase non-linear hunting workflow with the critical thinking framework (developer psychology, anomaly detection, What-If experiments). Routes to all other skills based on current hunting phase. Also use when asking "what should I do next" or "where am I in the process."
---
# Bug Bounty Methodology: Workflow + Mindset
Master orchestrator for hunting sessions. Combines the 5-phase non-linear workflow with the critical thinking framework that separates top 1% hunters from the rest.
---
## PART 1: MINDSET (How to Think)
### Core Principle
Hunting is not "find a bug" -- it is "prove an attack scenario." Think like an attacker with a specific goal, not a scanner looking for patterns.
### Daily Discipline: Define, Select, Execute
Before touching any tool:
1. **Define**: "Today I target [feature/domain] to achieve [CIA impact]"
2. **Select**: Choose 1-2 vuln classes (IDOR, Race Condition, etc.)
3. **Execute**: Focus ONLY on selected techniques. No wandering.
### 5 Ultimate Goals (Pick One Per Session)
1. **Confidentiality** -- steal data the attacker shouldn't see
2. **Integrity** -- modify data the attacker shouldn't change
3. **Availability** -- disrupt service (app-level DoS only)
4. **Account Takeover** -- control another user's account
5. **RCE** -- execute commands on the server
### 4 Thinking Domains
#### 1. Critical Thinking (deep analysis)
**Question trust boundaries:**
- Frontend control disabled? Send request directly via proxy
- `user_role=user` cookie? Change to `admin`
- `price=1000` in POST? Change to `1`
- `<script>` blocked? Try `<img onerror=...>`
**Reverse-engineer developer psychology:**
- Feature A has auth checks -> Similar feature B (newly added) probably doesn't
- Complex flows (coupon + points + refund) -> Edge cases have bugs
- `/api/v2/user` exists -> Does `/api/v1/user` still work with weaker auth?
**What-If experiments:**
- Skip checkout -> hit `/checkout/success` directly
- Skip 2FA -> navigate to `/dashboard`
- Send coupon request 10x simultaneously -> Race condition?
- Replace `guid=f8a2...` with `id=100` on sibling endpoint -> IDOR?
#### 2. Multi-Perspective (multiple angles)
| Perspective | What to check |
|------------|---------------|
| Horizontal (same role) | User A's token + User B's ID -> IDOR |
| Vertical (different role) | Regular user -> `/admin/deleteUser` |
| Data flow (proxy view) | Hidden params in JSON: `debug=false`, `discount_rate` |
| Time/State | Race conditions, post-delete session reuse |
| Client environment | Mobile UA -> legacy API with weaker auth |
| Business impact | "What's the $ damage if this breaks?" |
#### 3. Tactical Thinking (pattern detection)
- **Naming anomaly**: `userId` everywhere but suddenly `user_id` -> different dev, weaker security
- **Error diff**: Same 403 but different JSON structure -> different backend systems
- **Environment diff**: Prod vs Dev/Staging -> debug headers, CSP disabled
- **Version diff**: JS file before/after update -> new endpoints, removed params
- **Supply chain**: Check framework/library versions for known CVEs
- **Third-party integration**: Stripe/Auth0/Intercom -> webhook signature missing?
#### 4. Strategic Thinking (big picture)
- **Asymmetry**: Defender must patch ALL holes. You only need ONE.
- **Intuition engineering**: Log why something "feels wrong." Verify later. Update mental DB.
- **Unknown management**: Can't understand something? Add to "investigate later" list. Just-in-Time Learning.
### Amateur vs Pro: 7-Phase Comparison
| Phase | Amateur | Pro |
|-------|---------|-----|
| Recon | Main domain only | Shadow IT, dev environments, all assets |
| Discovery | Look for errors | Look for design contradictions, business logic flaws |
| Exploit | Give up when blocked | Build filter-bypass payloads |
| Escalation | Report the phenomenon only | Chain to real harm (session steal, ATO) |
| Feasibility | Include unrealistic conditions | Minimize attack prerequisites |
| Reporting | State facts only | Quantify business risk |
| Retest | Check if old PoC fails | Analyze fix method, find incomplete patches |
### Two Approach Routes
- **Route A (Feature-based)**: "This feature is complex" -> deep-dive its input handling -> find vuln
- **Route B (Vuln-based)**: "I want IDOR" -> find endpoints with sequential IDs -> test access control
### Anti-Patterns (Stop Doing These)
- **Program hopping**: Stick with one target minimum 2 weeks / 30 hours
- **Tool-only hunting**: Automation finds duplicates. Manual testing finds unique bugs.
- **Rabbit hole**: Max 45 min per parameter. Set a timer. If stuck, sleep on it.
- **No goal**: "Just looking around" = wasted time. Always Define first.
---
## PART 2: WORKFLOW (What to Do)
### The 5-Phase Non-Linear Flow
```
+-------------------------------------------------+
| |
| +----------+ +----------+ +----------+ |
| | 1. RECON |---+| 2. MAP |---+| 3. FIND | |
| +----------+ +-----+----+ +-----+-----+ |
| ^ | | |
| | v v |
| | +----------+ +----------+ |
| +----------| 4. PROVE |---+| 5. REPORT| |
| +----------+ +----------+ |
| |
| Non-linear: stuck at any phase -> go back |
| New API found at phase 3 -> return to phase 2 |
| WAF blocks at phase 4 -> origin IP from phase 1 |
+-------------------------------------------------+
```
**THIS IS NOT LINEAR.** Move freely between phases. When stuck, return to a previous phase.
### Phase 0: SESSION START (Every Time)
**Before touching any tool, answer these:**
1. **Define**: "Today I target [feature/domain] to achieve [C/I/A/ATO/RCE]"
2. **Select**: Choose 1-2 vuln classes (IDOR, XSS, SSRF, etc.)
3. **Execute**: Focus ONLY on selected techniques
4. **Identity**: Anonymous or authenticated? If the bugs you're hunting need a
session (IDOR, BOLA, privilege escalation, auth bypass, mass-assignment),
load auth **once** at session start — see `docs/auth-sessions.md`. Then
every downstream tool (httpx, katana, ffuf, nuclei, dalfox, PoC verifiers)
sends those headers automatically and audit log entries are stamped with
a stable `session_id` hash.
**Route selection -- Wide or Deep?**
| Signal | Wide (recon sweep) | Deep (focused testing) |
|--------|-------------------|----------------------|
| New program, first day | X | |
| Wildcard scope `*.target.com` | X | |
| Main webapp, been here >3 days | | X |
| Scope update (new domain added) | X | |
| Found interesting subdomain | | X |
| Hunting IDOR / BOLA / auth bugs | | X (auth-aware) |
### Phase 1: RECON
**Goal**: Maximize attack surface. Find what others missed.
**Wide approach** (initial sweep):
```
Subdomain enum -> DNS resolution -> HTTP probing -> Port scan -> Tech detect
```
**Deep approach** (targeted):
```
Google Dorks -> JS file download -> Hidden param discovery -> API mapping
```
| What you find | Next action |
|--------------|-------------|
| Live subdomains with tech stack | Phase 2 (Mapping) |
| Known software (WordPress, Jira) | Check CVEs + defaults immediately |
| Cloud resources (S3, Firebase) | Test permissions (read/write/list) |
| Nothing after 5 min on a host | Skip, try next host (5-minute rule) |
**Command**: `/recon target.com`
### Phase 2: MAPPING & ANALYSIS
**Goal**: Understand the app like its developer does.
**Checklist:**
- [ ] Map all endpoints (Burp/Caido sitemap + JS analysis)
- [ ] Identify auth model (cookie, JWT, OAuth, SAML?)
- [ ] Find business-critical flows (payment, registration, password reset, data export)
- [ ] Download and analyze JS files for hidden routes, secrets, logic
- [ ] Identify roles and permissions (user, admin, API keys)
- [ ] Note "weird" behaviors (anomalies in naming, errors, timing)
| What you find | Next action |
|--------------|-------------|
| JS files with interesting code | Taint analysis (Sink -> Source) |
| OAuth/SAML authentication | OAuth/SAML checklist |
| API with ID parameters | Phase 3, target IDOR |
| Complex business logic (payment, coupon) | Phase 3, target BizLogic |
| postMessage listeners | DOM analysis, postMessage-tracker |
### Phase 3: VULNERABILITY DISCOVERY
**Goal**: Find the bug. Use Error-based first, then Blind-based.
**Decision flow based on what you're testing:**
```
What input are you testing?
+-- ID parameter (user_id, order_id)
| -> IDOR checklist
+-- Search/filter/sort field
| -> SQLi, NoSQLi probing
+-- URL input / webhook / PDF gen
| -> SSRF checklist
+-- Text field reflected in page
| -> XSS (DOM or reflected)
+-- File upload
| -> SVG XSS, web shell, path traversal
+-- Price/quantity/coupon
| -> Business logic, race conditions
+-- Login / 2FA / password reset
| -> Auth bypass
+-- Profile update API
| -> Mass Assignment
+-- Template / wiki editor
| -> SSTI
+-- Nothing obvious
-> Fuzz with ffuf, try Error-based probing
```
**Error vs Blind decision:**
1. Try Error-based first (send `'`, `"`, `{{7*7}}`, `${7*7}`) -- watch for 500 errors, stack traces
2. No error? Time-based (`SLEEP(10)`, `; sleep 10;`) -- watch response time
3. No time diff? OOB (`curl attacker.com`, interactsh) -- watch for DNS callback
4. Still nothing? Boolean (`AND 1=1` vs `AND 1=0`) -- watch content-length diff
| What you find | Next action |
|--------------|-------------|
| Low-impact behavior (redirect, self-XSS, cookie injection) | Chain it -- find a connector gadget |
| Confirmed vuln (XSS, IDOR, SQLi) | Phase 4 (Prove and Escalate) |
| Blocked by WAF/CSP/403 | Bypass techniques, then retry |
| Known software vuln (CVE) | 1-day speed workflow |
| Nothing after 20 min on this endpoint | Rotate (20-minute rule) |
### Phase 4: PROVE & ESCALATE
**Goal**: Prove maximum business impact. Turn Low into Critical.
**Escalation decision:**
```
What did you find?
+-- XSS
| +-- Can steal cookie/token? -> Session hijack -> ATO
| +-- Cookie is HttpOnly? -> Force email change via XHR -> ATO
| +-- Self-XSS only? -> Find CSRF to trigger it
+-- IDOR
| +-- Can read PII? -> Automate scraping, show scale
| +-- Can change password/email? -> Direct ATO
| +-- UUID only? -> Find UUID leak source, then retry
+-- SSRF
| +-- DNS only? -> DON'T REPORT. Try cloud metadata
| +-- Can reach 169.254.169.254? -> Extract keys -> RCE
| +-- Internal port scan? -> Find Redis/K8s -> RCE
+-- SQLi
| +-- Error-based? -> Extract data (passwords, tokens)
| +-- Can INTO OUTFILE? -> Web shell -> RCE
| +-- Blind? -> Boolean/Time extraction
+-- Open Redirect
| +-- OAuth flow? -> Token theft -> ATO
| +-- javascript: scheme? -> XSS
+-- Blocked by defense
| -> Bypass (WAF/CSP/proxy/sanitizer/2FA)
+-- Low-impact, can't escalate alone
-> Find connector gadget for chain
```
**After proving impact, check:**
- [ ] Can attack work with 0-1 clicks? (minimize prerequisites)
- [ ] Does it affect all users or specific role?
- [ ] What's the business $ impact?
### Phase 5: VALIDATE & REPORT
**Goal**: Get paid. Make triager's job easy.
**Pre-report gate:**
```
Run /validate (7-Question Gate)
+-- All 7 pass? -> Write report
+-- Any fail? -> KILL the finding. Don't waste time.
+-- Borderline? -> Run /triage for quick go/no-go
```
**Report:**
```
Run /report
+-- Platform-specific format (H1/Bugcrowd/Intigriti/Immunefi)
+-- Title: [Bug Class] in [Endpoint] allows [role] to [impact]
+-- Impact-first summary (sentence 1 = what attacker CAN do)
+-- Exact HTTP requests in Steps to Reproduce
+-- Under 600 words
+-- CVSS 3.1 score that MATCHES actual impact
```
**After submission:**
- [ ] While waiting for triage: try to escalate further (A->B signal method)
- [ ] If fix deployed: re-test for bypass (incomplete patch = new bug)
- [ ] Record finding with `/remember` for hunt memory
---
## PART 3: NAVIGATION & TIMING
### Non-Linear Navigation Quick Reference
| I'm stuck because... | Go to... |
|----------------------|----------|
| Can't find any subdomains | Phase 1: Try different recon sources, Google Dorks |
| Found subdomain but don't know what to test | Phase 2: Map the app, download JS, understand auth |
| Testing but nothing works | Phase 3: Switch vuln class (20-min rotation rule) |
| Found a bug but impact is low | Phase 4: Escalation paths or gadget chaining |
| WAF/CSP/403 blocking my payload | Bypass techniques, then return to current phase |
| Been stuck for 45 min on one param | STOP. Rabbit hole. Move to next endpoint. |
| New API endpoint discovered during testing | Return to Phase 2: map it before attacking |
| Found one bug | A->B signal: same dev made more mistakes. Hunt 20 min for siblings. |
### 20-Minute Rotation Clock
Every 20 minutes ask yourself: **"Am I making progress?"**
- Yes -> Continue
- No -> Rotate to next: endpoint -> subdomain -> vuln class -> target
- Been on same target 2+ weeks with no findings? -> Consider switching program
### Tool Routing by Phase
| Phase | Tools | Why this order |
|-------|-------|----------------|
| Recon: Subdomains | `subfinder` -> `amass` -> `puredns` -> `httpx` | Passive first (no detection) -> resolve DNS -> probe HTTP + tech stack |
| Recon: URLs | `gau` + `waymore` -> `katana` -> `uro` | Archive (forgotten endpoints) -> active crawl (JS-rendered) -> deduplicate |
| Recon: JS | `jsluice` + `mantra` + `trufflehog --only-verified` | Extract URLs/secrets -> find API keys -> verify keys actually work |
| Recon: Ports | `naabu` (wide) -> `rustscan` (deep) | Fast top-1000 sweep -> full 65535 on interesting targets |
| Recon: Scan | `nuclei -tags cve` -> `nuclei -tags takeover` | Known CVEs first -> then takeover (act immediately) |
| Mapping: Params | `arjun` + `paramspider` + ParamMiner | Brute-force hidden params + mine archives + cache headers |
| Mapping: JS code | Download -> `jsluice` -> VS Code/Cursor grep | Extract -> static analysis -> AI-assisted taint analysis |
| Mapping: Dorks | Manual Google Dorks | Custom per-target queries find what automation misses |
| Discovery: Fuzz | `ffuf -ac` + `cewl` custom wordlist | Auto-calibrate filtering + target-specific words beat generic lists |
| Discovery: XSS | `kxss` -> `dalfox` | Filter (which params reflect?) -> scan (only reflective params) |
| Discovery: SQLi | `ghauri` | Modern blind SQLi on ID-like parameters |
| Discovery: SSRF | `interactsh-client` | Self-hosted OOB listener for blind SSRF/XXE/RCE |
| Discovery: WAF | `wafw00f` -> `whatwaf` | Identify WAF vendor -> test bypass techniques |
| Exploit: 403 | `byp4xx` or `nomore403` | 20+ bypass techniques automated |
| Exploit: Takeover | `subzy` | Checks CNAME against 70+ vulnerable services |
| Exploit: Cloud | `s3scanner` + `aws` CLI | Scan bucket permissions -> extract metadata credentials |
| Exploit: Secrets | `trufflehog --only-verified` | Only verified working keys (no false positives) |
### Session End Checklist
- [ ] Save all Burp/Caido project files
- [ ] Record any "weird but not yet exploitable" behaviors (future gadgets)
- [ ] Update notes with failed attempts (don't re-test with same techniques)
- [ ] Log findings with `/remember`