dotnet-reverse

A workflow for examining compiled .NET and C# programs, including Windows executables and libraries, to recover their code and behavior.

In plain words
What is it for?
It helps inspect, deobfuscate, debug, and modify authorized .NET software, including loaders, red-team tools, malware, and Unity programs that still contain a managed .NET layer.
Why use it?
Compiled programs do not directly show their original source, and code obfuscation can make analysis harder; this workflow identifies the program type and guides the appropriate tools.

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/asaiuta/reverse-workbench-skill/dotnet-reverse
Any agent
npx skills add Asaiuta/reverse-workbench-skill --skill dotnet-reverse
Clone the repo
git clone --depth 1 https://github.com/Asaiuta/reverse-workbench-skill

Made for: Claude Code, Codex.

Per session 144 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,980 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod 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 $0.00144 $0.02980
Opus 5 $0.00072 $0.01490
Sonnet 5 $0.00029 $0.00596
Haiku 4.5 $0.00014 $0.00298

Measured yesterday against content hash 12154b4dd685, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

dotnet-reverse 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 yesterday.

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.

Origin

This is a copy

100% identical to dotnet-reverse — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/dotnet-reverse/SKILL.md · 193 lines

How it starts

The opening of the file, as written. The whole thing — 193 lines — stays where its author put it; the contents beside it link to each section on GitHub.

.NET / C# 逆向作业规范

ACTION REQUIRED(读完立刻执行)

  1. NOW: 用 DIE/file/CLR 头确认目标是 .NET 托管(否则 SWITCH 到 ida-reverse/ / reverse-engineering/
  2. NOW: 若疑似混淆 → 先 de4dot 脱壳,产出 *-clean.exe,保留原始样本
  3. NEXT: dnSpyEx(或 dnSpy MCP / ilspycmd)静态:C# 浏览 + IL 视图看关键判断
  4. ACT: 需要明文/C2 时动态调试;需要改逻辑时 IL patch 优先于 C# 重编译
  5. 阶段结束给用户 3–6 项下一步菜单(含导出报告)

适用范围

当任务属于以下场景时优先使用本 skill:

  • 识别并逆向 .NET / C# 编译产物(托管 PE / .exe / .dll)
  • 分析红队 Sharp* 工具链(Rubeus、SharpHound、SharpShell 等)
  • 脱混淆 ConfuserEx / SmartAssembly / Babel / Eazfuscator / .NET Reactor 等壳
  • 逆向 .NET loader / info-stealer / RAT 的解密与 C2 逻辑
  • 对 C# 程序做 patch(改判断、改常量、keygen)
  • 分析 IL2CPP 之前的 Mono/Unity 托管层(注意:IL2CPP 编译后是 native,走 reverse-engineering/ + seed-014)

如果目标是纯 native 二进制(C/C++/Go/Rust 编译、无 CLR),请改用 reverse-engineering/ida-reverse/radare2/

核心原则

  • 先识别再下手:先确认是 .NET 托管程序(PE 头 CLR + #~ / #Strings 流 + mscoree _CorExeMain),再决定走 dnSpy 而非 IDA
  • IL 优先于 C#:dnSpyEx 的 C# 反编译器会丢失/扭曲信息(编译器生成的状态机、async/await、yield),关键判断与 patch 必须切到 IL 编辑器,C# 视图只用于快速浏览
  • de4dot 先行:遇到混淆器先 de4dot 脱一轮再做静态分析,否则字符串/控制流全是乱的
  • MCP 联动:环境里若注册了 dnSpy MCP(dnspy_* 工具),优先走 MCP 面做 decompile / IL inspection,避免来回切 GUI
  • 证据化输出:脱混淆产物、提取的配置/C2/key、patch diff 都要落盘

工具链映射

能力 首选 备注
反编译 + 调试 + patch dnSpyEx 王牌,唯一带 IL 编辑器的 GUI;老 dnSpy 已停更,用 Ex 分支
轻量 CLI / headless 反编译 ILSpy (ilspycmd) 适合批量、脚本化、Linux/macOS
脱混淆 de4dot ConfuserEx 全家桶、SmartAssembly 等主流壳的默认解
混淆器识别 Detect It Easy (DIE) / file 先判断壳类型再决定 de4dot 参数
编程化操作 IL dnlib 写 C# 脚本批量改 metadata / 字符串解密器
AI 直接操作 dnSpy MCP dnspy_decompile / dnspy_inspect_il 等工具面

前置:Windows 主机装 dnSpyEx + de4dot(choco 或 release);Linux/macOS 用 ilspycmd + dotnet runtime。详见 references/sharp-tools.md 的安装矩阵。

六阶段工作流

1. Identify(识别 .NET)

确认目标是托管程序,别把 native PE 当 .NET 分析:

# Windows
file target.exe                       # "PE32 executable ... for MS Windows" 不够
# 关键:看有没有 CLR
powershell -c "[System.Reflection.AssemblyName]::GetAssemblyName('target.exe')"
# 或
dnSpyEx 直接拖进去 —— 能打开就是托管

# 通用
strings target.exe | grep -iE "mscoree|_CorExeMain|mscorlib|System\\."

Read the full file on GitHub · 193 lines

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. yesterday First seen · 193 lines · 144 tokens per session scan A 12154b4dd685

Subscribe to this mod's changes

dotnet-reverse is a skill published in the GitHub repository Asaiuta/reverse-workbench-skill (1 stars, last pushed 18d ago), licensed MIT. It adds 144 tokens to every session and 2,980 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to dotnet-reverse, differing in 0 lines, and is treated as a copy.