HackSkills is an organized knowledge base of installable skills that gives AI agents practical security knowledge across areas such as web security, privilege escalation, reverse engineering, and digital forensics. It is intended for bug bounty work, penetration testing, CTF competitions, and authorized security research. The catalogue entries are the project's own master, category, and topic skills.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add yaklang/hack-skills --skill browser-exploitation-v8git clone --depth 1 https://github.com/yaklang/hack-skillsWrote 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.
[](https://agentmods.dev/skills/yaklang/hack-skills/browser-exploitation-v8)<a href="https://agentmods.dev/skills/yaklang/hack-skills/browser-exploitation-v8"><img src="https://agentmods.dev/badge/skills/yaklang/hack-skills/browser-exploitation-v8.svg" alt="Measured on agentmods" height="20"></a>- Socket fail
- Snyk fail
- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Tool Misuse · line 291 Tool defaults are unsafe or overly permissive (e.g. disabled TLS verification, no authentication, world-writable permissions). Unsafe defaults widen the attack surface.Fix: Override unsafe defaults with secure settings (verify=True, auth required, restrictive permissions). Review and harden all tool configurations.
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00050 | $0.03036 |
| Opus 5 | $0.00025 | $0.01518 |
| Sonnet 5 | $0.00010 | $0.00607 |
| Haiku 4.5 | $0.00005 | $0.00304 |
Grade A, and why
browser-exploitation-v8 scanned grade A with 0 findings 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 8d ago.
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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
4 near-identical copies found in the catalogue:
- browser-exploitation-v8 — 100% identical, 0 lines differ
- browser-exploitation-v8 — 100% identical, 0 lines differ
- browser-exploitation-v8 — 100% identical, 0 lines differ
- browser-exploitation-v8 — 94% identical, 4 lines differ
How it starts
The opening of the file, as written. The whole thing — 335 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SKILL: Browser / V8 Exploitation — Expert Attack Playbook
AI LOAD INSTRUCTION: Expert V8/Chrome exploitation techniques. Covers V8 compilation pipeline, JIT type confusion, addrof/fakeobj primitives, ArrayBuffer corruption, WASM RWX pages, V8 sandbox (pointer compression), and Chrome sandbox escape overview. Distilled from ctf-wiki browser sections, Project Zero research, and CTF competition patterns. Base models often confuse V8 object representation details and miss the pointer compression barrier.
0. RELATED ROUTING
- sandbox-escape-techniques — Chrome renderer sandbox escape via IPC/Mojo
- heap-exploitation — general heap concepts applicable to V8 heap
- stack-overflow-and-rop — ROP concepts for native code execution after V8 escape
- binary-protection-bypass — ASLR/NX bypass in browser context
Advanced Reference
Load V8_EXPLOITATION_PATTERNS.md when you need:
- Detailed exploitation patterns and code templates
- Heap layout manipulation and GC interaction
- V8 sandbox bypass techniques
- Object map confusion patterns
1. V8 ARCHITECTURE
Compilation Pipeline
JavaScript Source
↓ Parser
AST (Abstract Syntax Tree)
↓ Ignition
Bytecode (interpreted, profiling)
↓ Sparkplug (non-optimizing baseline, V8 ≥ 9.1)
Baseline code (fast startup)
↓ Maglev (mid-tier, V8 ≥ 10.2)
Mid-optimized code
↓ TurboFan (optimizing JIT)
Optimized machine code (with speculative optimizations)
↓ Deoptimization (if speculation fails)
Back to Ignition bytecode
Key V8 Concepts
| Concept | Description |
|---|---|
| Tagged pointers | SMI (Small Integer): value << 1, HeapObject: ptr | 1 |
| Pointer compression | V8 ≥ 8.0: objects addressed via 32-bit offset from cage base (4GB sandbox) |
| Maps (Hidden Classes) | Define object shape: property names, types, offsets |
| Elements kinds | Internal array type: PACKED_SMI_ELEMENTS, PACKED_DOUBLE_ELEMENTS, PACKED_ELEMENTS, etc. |
| Write barrier | GC bookkeeping when heap pointers are written |
| Garbage collection | Orinoco GC: minor (Scavenge) and major (Mark-Compact) |
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.
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.
- 8d ago First seen · 335 lines · 50 tokens per session scan A 47a589e8a3dd
browser-exploitation-v8 is a skill published in the GitHub repository yaklang/hack-skills (2,120 stars, last pushed 2mo ago), licensed MIT. It adds 50 tokens to every session and 3,036 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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