The first payload I came up with for the DarkDuino was a simple powershell payload to download a given file off the network and then to execute it. I will co over the code in detail below. This is the main loop in a sketch uploaded to an Arduino Micro Microcontroller. At a high level what happens is, when connected to a target system and pinButton is pressed (brought to GND) the DarkDuino fires off a powershell command to download a python file and execute it. It does assume the network allows local area network traffic on port 80 or 443 if you're using HTTPS (and you should be!). It also assumes that the system has the python executable in it's PATH. here is the commented code:
