reverse-engineering-arm-binaries

reverse-engineering-arm-binaries is a skill for Claude Code, Codex from meltedinhex/analyst-ai-pack. It costs 69 tokens per session (720 once invoked), scanned A, original, Apache-2.0.

A guide to analysing malware compiled for ARM or AArch64 processors, the chip families used in many phones, routers, and embedded devices.

In plain words
What is it for?
Use it to identify an ARM binary's format and entry point, distinguish ARM from Thumb instructions, and follow how functions receive arguments and return values.
Why use it?
It prevents analysis errors caused by using the wrong instruction mode or calling convention. The process reads the binary without running it.

Skill for Claude CodeCodex

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

Good fit Use it to identify an ARM binary's format and entry point, distinguish ARM from Thumb instructions, and follow how functions receive arguments and return values.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/meltedinhex/analyst-ai-pack/reverse-engineering-arm-binaries
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.

Any agent
npx skills add meltedinhex/analyst-ai-pack --skill reverse-engineering-arm-binaries
Clone the repo
git clone --depth 1 https://github.com/meltedinhex/analyst-ai-pack

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 reverse-engineering-arm-binaries

README.md
[![agentmods](https://agentmods.dev/badge/skills/meltedinhex/analyst-ai-pack/reverse-engineering-arm-binaries.svg)](https://agentmods.dev/skills/meltedinhex/analyst-ai-pack/reverse-engineering-arm-binaries)
Your own site
<a href="https://agentmods.dev/skills/meltedinhex/analyst-ai-pack/reverse-engineering-arm-binaries"><img src="https://agentmods.dev/badge/skills/meltedinhex/analyst-ai-pack/reverse-engineering-arm-binaries.svg" alt="Measured on agentmods" height="20"></a>
Per session 69 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 720 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00069 $0.00720
Opus 5 $0.00034 $0.00360
Sonnet 5 $0.00014 $0.00144
Haiku 4.5 $0.00007 $0.00072

Measured 4d ago against content hash e899d74a7619, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

reverse-engineering-arm-binaries 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 4d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/analyst.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.

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-arm-binaries/SKILL.md · 90 lines

What it actually says

Reverse Engineering ARM Binaries

When to Use

  • You have an ARM (32-bit) or AArch64 (64-bit) binary — IoT/mobile/Linux malware — and need to identify the architecture, instruction-set state, and entry point before disassembly.
  • You need to handle ARM/Thumb interworking correctly.

Do not use an x86 mindset for calling conventions/registers — ARM differs. This skill reads the binary statically and executes nothing.

Prerequisites

  • The ARM binary (ELF or Mach-O), read inertly. Capstone optional for instruction decoding.

Safety & Handling

  • Read bytes statically; analyze on an isolated host (and emulate via QEMU separately if needed).

Workflow

Step 1: Identify architecture and format

python scripts/analyst.py identify sample.bin

Parses ELF/Mach-O headers to report ARM vs AArch64, endianness, entry point, and (for ELF) whether the entry is Thumb (low bit set in e_entry or $t mapping symbols).

Step 2: Set the correct disassembly mode

Disassemble AArch64 as A64; for 32-bit ARM, switch between ARM and Thumb per the entry/mapping symbols.

Step 3: Orient around the calling convention

Track arguments in r0-r3/x0-x7, return in r0/x0, and syscalls via svc with the syscall number in r7/x8.

Step 4: Proceed with analysis

Identify functions, strings, and syscalls; pair with emulation if dynamic insight is needed.

Validation

  • Architecture (ARM/AArch64) and endianness are read from the header.
  • The entry point and ARM/Thumb state are reported.
  • Disassembly mode matches the detected state.

Pitfalls

  • Missing Thumb state and decoding Thumb as ARM (garbage output).
  • Big-endian ARM (rare but real) mis-parsed as little-endian.
  • Statically linked musl/uClibc inflating the function set on IoT samples.

References

Files

What ships with it

3 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. 4d ago First seen · 90 lines · 69 tokens per session scan A e899d74a7619

Subscribe to this mod's changes

reverse-engineering-arm-binaries is a skill published in the GitHub repository meltedinhex/analyst-ai-pack (22 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 69 tokens to every session and 720 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 2026-09-03.

Related

Other skills, from other repositories

analyzing-golang-malware-with-ghidra

Reverse engineer Go-compiled malware in Ghidra by parsing Go buildinfo and pclntab structures, recovering stripped/obfuscated function names (e.g. via GoResolver), and extracting embedded module/dependency strings and types from Go binaries. Use when analyzing a Go-language malware sample, deobfuscating a…

mukul975/Anthropic-Cybersecurity-Skills · 95 tokens

analyzing-malicious-pdf-with-peepdf

Perform static analysis of malicious PDF documents using peepdf, pdfid, and pdf-parser to extract embedded JavaScript, shellcode, and suspicious objects.

26zl/cybersec-toolkit · 43 tokens

analyzing-malicious-pdf-with-peepdf

Perform static analysis of malicious PDF documents using peepdf, pdfid, and pdf-parser to extract embedded JavaScript, shellcode, and suspicious objects.

autohandai/community-skills · 43 tokens

analyzing-golang-malware-with-ghidra

Reverse engineer Go-compiled malware in Ghidra by parsing Go buildinfo and pclntab structures, recovering stripped/obfuscated function names (e.g. via GoResolver), and extracting embedded module/dependency strings and types from Go binaries. Use when analyzing a Go-language malware sample, deobfuscating a…

Youngmaidainon/Agent-Level-Up · 95 tokens

analyzing-malicious-pdf-with-peepdf

Perform static analysis of malicious PDF documents using peepdf, pdfid, and pdf-parser to extract embedded JavaScript, shellcode, and suspicious objects. Use when triaging a suspicious PDF attachment from a phishing email, analyzing a PDF-based exploit document, or building detection signatures for weaponized PDF…

Youngmaidainon/Agent-Level-Up · 73 tokens

analyzing-malicious-pdf-with-peepdf

Perform static analysis of malicious PDF documents using peepdf, pdfid, and pdf-parser to extract embedded JavaScript, shellcode, and suspicious objects.

RobotFlow-Labs/skills-repo · 43 tokens