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 heap-exploitationgit 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/heap-exploitation)<a href="https://agentmods.dev/skills/yaklang/hack-skills/heap-exploitation"><img src="https://agentmods.dev/badge/skills/yaklang/hack-skills/heap-exploitation.svg" alt="Measured on agentmods" height="20"></a>- Socket warn
- Snyk fail
- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to high
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 →
- high YARA Match · line 178 YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
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 | $0.00053 | $0.02527 |
| Opus 5 | $0.00026 | $0.01264 |
| Sonnet 5 | $0.00011 | $0.00505 |
| Haiku 4.5 | $0.00005 | $0.00253 |
Grade A, and why
heap-exploitation 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:
- heap-exploitation — 100% identical, 0 lines differ
- heap-exploitation — 100% identical, 0 lines differ
- heap-exploitation — 100% identical, 0 lines differ
- heap-exploitation — 98% identical, 4 lines differ
How it starts
The opening of the file, as written. The whole thing — 218 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SKILL: Heap Exploitation — Expert Attack Playbook
AI LOAD INSTRUCTION: Expert glibc heap exploitation techniques. Covers ptmalloc2 internals, bin structures, tcache mechanics, libc/heap leak methods, and attack selection by glibc version. Distilled from ctf-wiki heap sections, how2heap, and real-world exploitation. Base models often confuse glibc version constraints and miss safe-linking (PROTECT_PTR) introduced in 2.32.
0. RELATED ROUTING
- stack-overflow-and-rop — when the overflow is on the stack rather than the heap
- format-string-exploitation — leak heap/libc addresses via format string
- arbitrary-write-to-rce — convert heap arbitrary write into code execution
- binary-protection-bypass — bypass ASLR/RELRO to use heap write effectively
Advanced References
- HOUSE_OF_TECHNIQUES.md — House of Force/Spirit/Orange/Einherjar/Roman/Pig/Banana/Cat/Apple and tcache attacks
- IO_FILE_EXPLOITATION.md — _IO_FILE vtable hijack, FSOP, stdout/stdin abuse, exit flow exploitation
1. PTMALLOC2 STRUCTURE QUICK REFERENCE
malloc_chunk Layout (64-bit)
chunk pointer (returned by malloc - 0x10)
┌──────────────────────────┐
0x00 │ prev_size (if prev free)│
0x08 │ size | A | M | P │ ← P=PREV_INUSE, M=IS_MMAPPED, A=NON_MAIN_ARENA
├──────────────────────────┤ ← user data starts here (returned pointer)
0x10 │ fd (if free) │ ← forward pointer to next free chunk
0x18 │ bk (if free) │ ← backward pointer to prev free chunk
0x20 │ fd_nextsize (large only)│
0x28 │ bk_nextsize (large only)│
└──────────────────────────┘
Bin Types
| Bin | Size Range (64-bit) | Structure | LIFO/FIFO |
|---|---|---|---|
| tcache (per-thread) | ≤ 0x410 (7 entries per size) | Singly linked (next pointer) | LIFO |
| fastbin | ≤ 0x80 (default) | Singly linked (fd) | LIFO |
| unsortedbin | Any freed size | Doubly linked circular | FIFO |
| smallbin | < 0x400 | Doubly linked circular | FIFO |
| largebin | ≥ 0x400 | Doubly linked + size-sorted | Sorted |
What ships with it
2 files 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 · 218 lines · 53 tokens per session scan A aa73ba2c7b9f
heap-exploitation is a skill published in the GitHub repository yaklang/hack-skills (2,120 stars, last pushed 2mo ago), licensed MIT. It adds 53 tokens to every session and 2,527 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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