A couple of weeks ago I accidentally installed Civ 6 again, which reduced the time I have had available for other non-essential activity. Fortunately, I have just about had enough Civ for this round, which means that I should shortly have more time for things like RustRAT again. Progress has not halted to a complete stop, however, and rustrat-server is now more or less ready to receive incoming connections over HTTP. The server is not very usable at the moment, and before I have something even remotely ready for testing, basic logging and some interface to actually interact with the rats is needed.

The libffi bindings are now working, which means that RustRAT is now able to execute WebAssembly binaries, and those binaries can call arbitrary functions from dlls. I have also uploaded the code to github, so it is possible to follow the progress at https://github.com/rustrat/rustrat. In this post I will briefly mention what has been done so far, the next step on the way to a full-fledged RAT, and finally a little guide on how to call MessageBoxA from a WebAssembly binary. The present Currently RustRAT is not very exciting, but it is possible to demonstrate the libffi capabilities. The “rustrat-client” executables can be used to execute WebAssembly binaries, for example from the “demo-messagebox” crate, which will call MessageBoxA.