reverse-engineering-dotnet-malware-with-dnspy
Installation
SKILL.md
Reverse Engineering .NET Malware with dnSpy
When to Use
- A malware sample is identified as a .NET assembly (C#, VB.NET, F#) requiring decompilation
- Analyzing .NET-based malware families (AgentTesla, AsyncRAT, RedLine Stealer, Quasar RAT)
- Deobfuscating .NET code protected by ConfuserEx, SmartAssembly, or custom obfuscators
- Extracting hardcoded C2 configurations, encryption keys, and credentials from managed assemblies
- Debugging .NET malware at runtime to observe decryption routines and dynamic behavior
Do not use for native (unmanaged) PE binaries; use Ghidra or IDA for native code analysis.
Prerequisites
- dnSpy or dnSpyEx installed (https://github.com/dnSpyEx/dnSpy - community maintained fork)
- de4dot for automated .NET deobfuscation (
https://github.com/de4dot/de4dot) - ILSpy as an alternative decompiler for cross-validation
- .NET SDK installed for recompiling modified assemblies during analysis
- Isolated Windows VM for running dnSpy debugger on live malware
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