what you are looking for is called a "rubby ducky". It was the name of the original Hak5 product for this tool. Essentially is a device (usb stick) that connects to a USB type A port and can switch between acting like a keyboard, file storage, and other device modes.
If you plan to use it for illegal activities. I would suggest making your own version of the rubber ducky. You should be able to figure out how to do this with some googling.
Make sure you source the parts used anonymously as you wouldn't want any device ids or serial number linking back to your identity if the rubber ducky falls into law enforcement's hands. There are some places where you can buy prepaid gift cards with crypto. Use something like that to order the parts to a drop address that isn't linked to you.