SharPyShell
Tiny and obfuscated ASP.NET webshell for C# web applications
... is not intended as a replacement for the frameworks for C2 Server (i.e. Meterpreter, Empire, etc..) but this should be used when you land on a fully restricted server where inbound and outbound connections are very limited. In this framework, you will have all the tools needed to privesc, net discovery, and lateral movement as you are typing behind the cmd of the target server.