dotnet-reverse – Data & Science skill for AI agents
.NET/C# binary reverse engineering: managed PE analysis, dnSpyEx debugging, de4dot deobfuscation (ConfuserEx/SmartAssembly/Babel), IL patching, NativeAOT targets, and analysis of red-team Sharp* tooling.
Install the dotnet-reverse skill with one command
Pick the tool you use, copy the command and paste it in your terminal. The skill lands in that tool's skills folder and is ready in your next session.
Claude Code
mkdir -p ~/.claude/skills && curl -fsSL https://skill.dn1nguoi.com/z/dotnet-reverse-c671b.tgz | tar xz -C ~/.claude/skills
Call it in Claude Code: /dotnet-reverse – then describe the task you want done.
Codex
mkdir -p ~/.codex/skills && curl -fsSL https://skill.dn1nguoi.com/z/dotnet-reverse-c671b.tgz | tar xz -C ~/.codex/skills
Call it in Codex: $dotnet-reverse – then describe the task you want done.
Hermes Agent
mkdir -p ~/.hermes/skills && curl -fsSL https://skill.dn1nguoi.com/z/dotnet-reverse-c671b.tgz | tar xz -C ~/.hermes/skills
Call it in Hermes Agent: /dotnet-reverse – then describe the task you want done.
DeepSeek
mkdir -p ~/.deepcode/skills && curl -fsSL https://skill.dn1nguoi.com/z/dotnet-reverse-c671b.tgz | tar xz -C ~/.deepcode/skills
Call it in DeepSeek: /dotnet-reverse – then describe the task you want done.
SKILL.md content
> ⚠️ AUTHORIZED USE ONLY
> This skill is for educational purposes or authorized security assessments only.
> You must have explicit, written permission from the system owner before using this tool.
> Misuse of this tool is illegal and strictly prohibited.
> Mandatory confirmation gate
> Before running any command that probes, exploits, changes, persists on, extracts data from, or attempts credential access against a target:
> 1. Ask the user to state the exact target URL, IP, account, or resource.
> 2. Ask the user to confirm written authorization and the permitted scope.
> 3. Show the exact command(s) and explain their expected effect.
> 4. Wait for explicit confirmation in the current conversation.
>
> Without that confirmation, remain read-only and provide defensive guidance only. Prefer a sandbox, disposable VM, or controlled lab.
.NET / C# 逆向作业规范
When to Use
- Analyzing a .NET assembly, obfuscated C# product, or native-AOT binary.
- Understanding the internals of Sharp* red-team tools before use or defense.
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/ 或 radare2/。
授权与隔离
仅分析有授权的样本。未知程序集、依赖与脱混淆器可能执行代码;使用无真实凭据、无共享目录的可回滚隔离虚拟机,默认阻断外联。静态元数据优先;动态执行必须单独确认范围。提取的密钥/C2按敏感证据保存,不连接或复用。patch另存副本并验证栈、分支、异常处理及签名,不覆盖原样本。
原版 de4dot 已归档且未列出 ConfuserEx 支持;下方旧版表格是候选线索,须核对所用 fork 的实际参数与支持范围。上游路由与 MCP 名称不表示本包已提供这些能力。
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\\.".NET 识别标志:
- PE 头
Data Directory[14](CLR Runtime Header) 非零 mscoree.dll导入 /_CorExeMain入口#~、#Strings、#US、#GUID、#Blobmetadata 流mscorlib/System.Private.CoreLib字符串
NativeAOT 例外: 编译成 native,没有 CLR 头,但有 System.Private.CoreLib 字符串和重构过的类型元数据 —— 这类走 reverse-engineering/(IDA/r2),本 skill 仅做识别提示。
2. Detect(检测混淆器)
# DIE 快速识别
diec target.exe # Detect It Easy CLI
# 或拖进 dnSpyEx,看是否大量乱码类名 / 控制流变形常见混淆器 → 脱壳策略(详见 references/obfuscators.md):
| 混淆器 | 特征 | de4dot 处理 |
|--------|------|------------|
| ConfuserEx (1.0.0 / 2.x) | <module> anti-tamper、控制流变形、字符串加密 | de4dot target.exe 通常自动识别 |
| SmartAssembly | circular/string encoding、资源压缩 | de4dot target.exe |
| Babel.NET | 方法体加密、控制流 | de4dot target.exe |
| Eazfuscator.NET | 字符串/资源加密 | de4dot,部分版本需手动 |
| .NET Reactor | anti-tamper + necrobit | de4dot,新版可能失败需手动 |
3. Deobfuscate(脱混淆)
# de4dot 默认自动识别大多数壳
de4dot target.exe -o target-clean.exe
# 指定类型(自动识别失败时)
# ConfuserEx: 核实专用 fork 的支持和参数后再使用
de4dot --type sa target.exe # SmartAssembly
# 多层混淆 / de4dot 报 unknown
de4dot --detect target.exe # 看它识别成什么
# 可能要先 patch anti-tamper 再 de4dot(见 references/obfuscators.md)产出:target-clean.exe,后续分析用它。保留原始样本做对照。
4. Static Analyze(静态分析)
dnSpyEx 加载脱壳后样本:
- C# 视图:快速浏览类结构、方法签名、字符串(用于定位)
- IL 视图:关键判断、加密逻辑、状态机必须看 IL(右键 → Edit IL 或 IL 视图)
- 找入口:
Main/Startup/ 模块初始化器 (Module .cctor) - 找关键逻辑:搜
flag、password、verify、check、encrypt、http、Config
定位字符串 → 反向引用 → 找到使用它的方法 → IL 视图看判断逻辑5. Dynamic(动态调试)
dnSpyEx 调试器:附加进程 / 启动调试,在关键方法下断点,观察运行时:
- 解密后的明文字符串(很多混淆器的字符串在运行时才解密)
- C2 地址、配置解密结果
- 异常驱动的控制流(anti-debug 常用
try/catch隐藏真实路径)
> .NET 动态调试比 native 友好得多 —— 能直接看到对象值、字符串内容。优先动态而非死磕静态。
6. Patch(按需修改)
dnSpyEx → 右键方法 → Edit Method (C#) 或 Edit IL
- 改判断:ldc.i4.0 → ldc.i4.1(false→true)
- 改常量:直接编辑字符串/数字
- 删除校验:nop 掉整段
File → Save Module → 另存 target-patched.exe,保留原始样本IL patch 可靠性 > C# patch:C# 重编译可能失败(缺引用、语法不对),IL 编辑仍可能破坏栈、分支或异常处理,必须验证。详见 references/common-workflow.md。
触发场景路由
用户说这些时进入本 skill:
- ".NET / C# 二进制逆向" / "C# 程序反编译"
- "dnSpy 分析" / "dnSpyEx patch"
- "ConfuserEx / SmartAssembly / Babel 脱混淆 / 脱壳"
- "Sharp* 工具分析"(Rubeus / SharpHound / SharpShell)
- ".NET malware / loader / info-stealer 逆向"
- "C# 程序 patch / keygen / 修改判断"
何时切出
- IL2CPP 编译的 Unity 游戏 →
reverse-engineering/+seed-014_unity-il2cpp-reverse.md(IL2CPP 是 native,不走 dnSpy) - NativeAOT 产物 →
reverse-engineering/(同上,native) - 纯 native PE(无 CLR)→
reverse-engineering//ida-reverse/ - 需要符号/函数批量迁移到别的版本 →
binary-diff/ - 需要画攻击路径 / 调用链图 →
diagram-generator/
路由上下文
上游入口: skills/SKILL.md(总控)、routing.md
下游出口:
- IL2CPP / NativeAOT(native)→
reverse-engineering/ - 深度 native .so/.dll 段分析 →
ida-reverse//radare2/ - 需要 AI 直接操作 dnSpy → 注册并联动 dnSpy MCP(见
references/sharp-tools.md)
同级关联模块:
reverse-engineering/languages-compiled.md(.NET 简介指向本模块)apk-reverse/(Xamarin/MAUI Android 逆向可切回本模块看 C# 层)
参考文档
- [references/obfuscators.md](references/obfuscators.md) — ConfuserEx / SmartAssembly / Babel / Eazfuscator / .NET Reactor 脱混淆详解 + anti-tamper 绕过
- [references/common-workflow.md](references/common-workflow.md) — 完整工作流、IL patch 可靠性、字符串解密器提取、状态机识别
- [references/sharp-tools.md](references/sharp-tools.md) — 红队 Sharp* 工具分析、工具安装矩阵、dnSpy MCP 集成、社区资源索引
任务完成自检
- [ ] 是否确认过 CLR / 托管身份(或已 SWITCH 出本 skill)?
- [ ] 混淆样本是否先 de4dot / 等价脱壳再深分析?
- [ ] 关键逻辑是否用 IL 视图验证(而非只看 C# 伪代码)?
- [ ] 产物(clean 样本 / 配置 / patch diff)是否落盘且可复现?
- [ ] 是否提供了下一步菜单或报告出口?
Limitations
- NativeAOT and trimmed builds lose most metadata; expect native-style RE.
- Some commercial obfuscators require manual unpacking steps.
> Adapted from [zhaoxuya520/reverse-skill](https://github.com/zhaoxuya520/reverse-skill) (MIT).
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