The QUACK Command
The Key Croc introduces enhancements to the Ducky Script keystroke injection command set – known as Ducky Script 2.0. This version builds on the ubiquitous language for keystroke injection that debuted with the USB Rubber Ducky and was further enhanced with the Bash Bunny.
The following are the basic “QUACK” commands – named in honor of the Rubber Ducky that invented the keystroke injection attack.
In order to use Ducky Script 2.0, or QUACK, in a payload the attack mode must contain the HID option. This is the default attack mode on boot. See the ATTACKMODE section for information on additional attack mode options.
DUCKY_LANG
Specified in the config.txt file on the root of the udisk partition (/root/udisk) – the DUCKY_LANG option configures the keyboard layout to be used in keystroke injection attacks. This is important to note as different computers and keyboards use different layouts around the world.
By default DUCKY_LANG is set to the US. Additional keyboard layouts are available from the languages directory on the Key Croc’s USB Flash Disk (udisk). Language key maps are specified using the two letter country code.
EXAMPLE
DUCKY_LANG DE
Q
Q is an alias for QUACK that may be used as shorthand substitution anywhere that QUACK may be used. Q does not have any further meaning and is otherwise not very impressive.
QUACK <KEY NAME>
There are nearly 2000 compatible keys which may be used directly with the QUACK command. For example, “QUACK y” will type “y”, and “QUACK ENTER” will press enter. Likewise, “QUACK CTRL-c” will hold the Control key and press c. Additionally, “QUACK N” will hold Shift and press n – since there is no capital N key on a keyboard.
For a complete list, edit the json file from the languages directory specified by your particular DUCKY_LANG. Any single key or key combination may be specified. Here are a few choice examples:
EXAMPLE
GUI r
CMD-SPACE
ALT-F2
CTRL-ALT-DELETE
TECHNICAL DETAIL
By default, QUACK will use the modifiers on the left side of the keyboard when injecting keystrokes. This behavior may be changed, either by modifying the language file or by using the keycode option with a specific modifier scan code. Both left and right side modifiers are specified in the language file for any given key combination/ The first instance is given priority.
For example, CTRL-c can be pressed with the Control key on the left, or on the right side of the keyboard. This will result in either “01,00,06” or “10,00,06” scan code.
QUACK STRING
STRING processes the text following taking special care to auto-shift. STRING can accept a single or multiple characters. There will be no ENTER or Carriage return key at the end of a STRING – so if one is desired it must be specified with its own QUACK command. STRING will automatically use SHIFT to capitalize a character.
EXAMPLE
QUACK STRING The Quick Brown Fox Jumped Over The Lazy Dog
QUACK STRING "This string has special characters! Isn't it great?"
See the notes at the end of this section on handling requirements for QUACK STRING as it relates to quotes and escaping special bash characters.
QUACK DELAY
DELAY creates a momentary pause in the ducky script. It is quite handy for creating a moment of pause between sequential commands that may take the target computer some time to process. DELAY time is specified in milliseconds from 1 to 10000. Multiple DELAY commands can be used to create longer delays.
EXAMPLE
QUACK GUI r
QUACK DELAY 500
QUACK STRING cmd /k tree c:\
QUACK ENTER
Note the 500 millisecond delay between the keyboard shortcut “GUI r” and the cmd command? That’s because it takes a few milliseconds for the run dialog to appear before we can inject keystrokes. We don’t typically think about these nuances as a human, but when you consider the Key Croc is one computer speaking to another, every millisecond counts.