Here are the most well-known tools for decompiling and analysis:

• ILSpy: This is a good decompiler for static analysis, but it doesn't have the ability to debug the malware.
• Dnspy: Based on ILSpy and dnlib, it's a decompiler that allows you to debug and patch the code.
• .NET reflector: A commercial decompiler tool for static analysis and debugging in Visual Studio.
• .NET IL Editor (DILE): Another powerful tool that allows for the disassembling and debugging of .NET applications.
• dotPeek: A tool that's used to decompile malware into C# code. Good for static analysis and for recompiling and debugging with the help of Visual Studio.
• Visual Studio: Visual Studio is the main IDE for .NET languages. It provides the ability to compile the source code and debug .NET applications.
• SOSEX: A plugin for WinDbg that simplifies .NET debugging.

Here are the most well-known deobfuscation tools:

• de4dot: Based on dnlib as well, it is very useful for deobfuscating samples...