This is a template project for building Cobalt Strike BOFs in Visual Studio.
If you prefer not to use the command line cl.exe or mingw32 and are used to working with an IDE, this project should help with that.
Just clone this repo and you can start writing code in bof.c, using the APIs detailed in this Cobalt Strike post.
If you change the default demo function name, then you will also need to change the entrypoint in the cna\hello.cna file.
The project settings are setup to compile a .lib file without linking it. There is then a post-build job that copies the .obj files into the cna\bin\ folder as bof.x64.o and bof.x86.o respectively.
Once you have built the .o files, you just need to modify the hello.cna to pack your arguments correctly and modify the entrypoint and alias and you are all set!
If you just want to give BOFs a try, first build the project in release mode for both x86 and x64, then copy the cna\ folder and load the hello.cna file in Cobalt Strike. In a beacon session type hello.
This is the default example from the Cobalt Strike blog.
You should see the following output printed if successful:
[+] received output:
Message is Hello World with 1234 arg