reverse-engineering

A reverse-engineering helper for examining compiled programs and bytecode—machine-readable instructions—to recover algorithms, validate inputs, or build solvers. It covers static analysis and selected runtime techniques such as Frida hooking.

In plain words
What is it for?
Use it to analyze ELF, PE, and Mach-O binaries, custom virtual machines, packed programs, control-flow obfuscation, mixed arithmetic logic, and encrypted handlers.
Why use it?
It helps when source code is unavailable, a program is heavily obfuscated, or running the original binary is unsafe, impractical, or blocked by anti-debugging measures.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/transilienceai/communitytools/reverse-engineering
Any agent
npx skills add transilienceai/communitytools --skill reverse-engineering
Clone the repo
git clone --depth 1 https://github.com/transilienceai/communitytools

Made for: Claude Code, Codex.

Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 356 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00032 $0.00356
Opus 5 $0.00016 $0.00178
Sonnet 5 $0.00006 $0.00071
Haiku 4.5 $0.00003 $0.00036

Measured 2d ago against content hash b47e61c9830b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

reverse-engineering 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 2d 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.

skills/reverse-engineering/SKILL.md · 23 lines

What it actually says

Reverse Engineering

Scope

Reverse engineering compiled binaries (ELF, PE, Mach-O) and bytecode artifacts to recover algorithms, validate inputs, or build static solvers. Focused on the recurring CTF / malware-analysis pattern of a host binary that loads a "program" file under a custom ISA — recognising the dispatcher loop, mapping opcodes to Python lambdas, and inverting the transformation chain in pure Python without executing the host. Also covers callfuscation (control-flow chunking), MBA (mixed boolean-arithmetic) operator obfuscation, encrypted-handler tricks, and three-layer deobfuscation pipelines.

When to use

  • A binary plus a "program data" file are delivered together and the binary appears to be an interpreter (themed opcode names, dispatcher switch / jump table).
  • Disassembly reveals a while(true){ op = mem[pc++]; switch(op){...}; } style loop or jump-table indexed by opcode.
  • The binary is heavily obfuscated (callfuscation, MBA wrappers, encrypted handlers in .data decrypted to RWX at startup).
  • You need to recover an algorithm or check function from native code without dynamic execution (anti-debug, wrong arch, no TTY).
  • Static-first reverse engineering is preferred (faster, more reliable than emulator chains).

References

  • reference/custom-vm-bytecode.md — recognising and inverting custom stack/register/tape VMs; callfuscation linearization; MBA operator identification; encrypted-handler decryption.
Files

What ships with it

25 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.

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. 2d ago First seen · 23 lines · 32 tokens per session scan A b47e61c9830b

Subscribe to this mod's changes

reverse-engineering is a skill published in the GitHub repository transilienceai/communitytools (498 stars, last pushed 1mo ago), licensed MIT. It adds 32 tokens to every session and 356 once invoked, about $0.0002 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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