dnSpy – NET Debugger & Assembly Editor

dnSpy

Reverse Engineer .NET Assemblies


dnSpy is a tool to reverse engineer .NET assemblies. It includes a decompiler, a debugger and an assembly editor (and more) and can be easily extended by writing your own extension. It uses dnlib to read and write assemblies so it can handle obfuscated assemblies (eg. malware) without crashing.

NET Debugger & Assembly Editor: dnSpy

NET Debugger & Assembly Editor: dnSpy

Features (see below for more detail)

  • Debug .NET Framework and .NET Core assemblies, no source code required
  • Edit assemblies in C# or Visual Basic or IL, and edit all metadata
  • Light and dark themes
  • Extensible, write your own extension
  • High DPI support (per-monitor DPI aware)
  • And much more, see below

dnSpy uses the ILSpy decompiler engine and the Roslyn (C# / Visual Basic) compiler and many other open source libraries, see below for more info.

Debugger

  • Debug .NET Framework and .NET Core assemblies, no source code required
  • Set breakpoints and step into any assembly
  • Locals, watch, autos windows
  • Variables windows supports saving variables (eg. decrypted byte arrays) to disk or view them in the hex editor (memory window)
  • Object IDs
  • Multiple processes can be debugged at the same time
  • Break on module load
  • Tracepoints and conditional breakpoints
  • Export/import breakpoints and tracepoints
  • Call stack, threads, modules, processes windows
  • Break on thrown exceptions (1st chance)
  • Variables windows support evaluating C# / Visual Basic expressions
  • Dynamic modules can be debugged (but not dynamic methods due to CLR limitations)
  • Output window logs various debugging events, and it shows timestamps by default ?
  • Assemblies that decrypt themselves at runtime can be debugged, dnSpy will use the in-memory image. You can also force dnSpy to always use in-memory images instead of disk files.
  • Public API, you can write an extension or use the C# Interactive window to control the debugger

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