Essential Skills — Deep Dive

Essential Skills — Deep Dive is a skill for Claude Code, Codex from ShulkwiSEC/bb-huge. It costs 24 tokens per session (822 once invoked), scanned A, original, MIT.

A broad PortSwigger-focused security-testing playbook with practical lab examples for finding and exploiting web vulnerabilities. It explains targeted scanning, which checks selected inputs instead of scanning an entire application.

In plain words
What is it for?
Preparing for BSCP certification, practising PortSwigger labs, testing selected request parameters, and studying web vulnerability chains.
Why use it?
Learners and testers need a repeatable way to investigate web applications while limiting unnecessary scans and noise. The supplied material focuses on hands-on vulnerability discovery and exploitation.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Needs its repository: it reads a path above its own folder, which exists only inside the repository. The line is - [`_shared/references/elite-chaining-strategy.md`](../_shared/references/elite-chaining-strategy.md) — Exploit chaining methodology and high-payout chain patte.

Good fit Preparing for BSCP certification, practising PortSwigger labs, testing selected request parameters, and studying web vulnerability chains.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/ShulkwiSEC/bb-huge
agentmods
npx agentmods add skills/shulkwisec/bb-huge/essential-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for Essential Skills — Deep Dive

README.md
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Your own site
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Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for Essential Skills — Deep Dive

Your own site · 80×15
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Per session 24 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 822 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00024 $0.00822
Opus 5 $0.00012 $0.00411
Sonnet 5 $0.00005 $0.00164
Haiku 4.5 $0.00002 $0.00082

Measured 7d ago against content hash 34476fee70e6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

Essential Skills — Deep Dive scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/process.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

tools: [burp-suite, curl, sqlmap, ffuf, python]
Origin

Copies of this mod

1 near-identical copy found in the catalogue:

skills/curated/essential-skills/SKILL.md · 86 lines

How it starts

The opening of the file, as written. The whole thing — 86 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Essential Skills — Deep Dive

Deep-Dive Lab Playbook — Every PortSwigger lab variant with exact payloads, bypass techniques, and zero-day extensions. 🟢 Apprentice 🟡 Practitioner 🔴 Expert

When to Use

  • BSCP certification prep
  • Real-world bug bounty hunting
  • Building exploitation chains

Prerequisites

  • Burp Suite Professional
  • Browser with proxy configured

Workflow

Phase 1: Reconnaissance

  • Identify input vectors, parameters, and application behavior.

Phase 2: Exploitation

  • Apply standard lab payloads.

Phase 3: Zero-Day Escalation

  • Fuzz filters, bypass WAFs, and chain with other vulns.

Lab Playbooks

Lab 1: Discovering vulnerabilities quickly with targeted scanning 🟡 PRACTITIONER

Use Burp Scanner's "Scan defined insertion points" feature on specific parameters rather than running a full crawl-and-scan which takes too long. Send a single request to Intruder or Scanner and only select the specific parameter (e.g., inside an XML node) to scan for vulnerabilities like XXE or SQLi.

Zero-day tip: Targeted scanning minimizes noise and risk of burning accounts compared to full automated scans.

Lab 2: Scanning non-standard data structures 🟡 PRACTITIONER

When dealing with custom or non-standard data (like a bespoke binary format or deep JSON encoding), use Burp extensions like JSON Web Tokens (JWT) or build a custom BApp. If standard insertion points don't work, use the "Bypass WAF" or "Hackvertor" extensions to auto-encode scanner payloads before they leave Burp.

Zero-day tip: Often, applications correctly sanitize standard form-data but fail to apply the same sanitization logic to Base64-encoded or custom-delimited data structures.

Key Concepts

Concept Description
PortSwigger Vectors Standardized approaches to vulnerability classes.
Payload Encoding Modifying payloads to bypass basic string matching WAFs.

Output Format

Vulnerability Deep-Dive Report
==============================
Target Vector: [Endpoint]
Bypass Technique: [Explanation of bypass]
Payload Used: [Payload]
Impact Explanation: [Impact]

Read the full file on GitHub · 86 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago First seen · 86 lines · 24 tokens per session scan A 34476fee70e6

Subscribe to this mod's changes

Essential Skills — Deep Dive is a skill published in the GitHub repository ShulkwiSEC/bb-huge (22 stars, last pushed 2mo ago), licensed MIT. It adds 24 tokens to every session and 822 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.