Attack Modes
Last updated
Last updated
An attack mode is the device type that a USB hotplug attack tool, like the USB Rubber Ducky, is functioning as. The original USB Rubber Ducky had only one mode: HID — functioning as a keyboard.
With the introduction of the Bash Bunny, a multi-vector attack tool, the ATTACKMODE command was introduced to the DuckyScript language to manage multiple device functions.
The new USB Rubber Ducky supports three attack modes — HID, STORAGE, and OFF.
| ATTACKMODE | Description |
|---|---|
The HID attack mode functions as a Human Interface Device (a keyboard) for keystroke injection.
The STORAGE attack mode functions as USB Mass Storage (a Flash Drive). This may be used for copying files to or from a target — often referred to as infiltration or exfiltration. In the STORAGE attack mode, the MicroSD card connected to the USB Rubber Ducky will be exposed to the target.
The OFF attack mode prevents the USB Rubber Ducky from being enumerated (seen) by the target as a connected device all together.
The ATTACKMODE command accepts multiple parameters which describe how the device will be enumerated by the target. At a minimum, a mode (HID, STORAGE or OFF) must be specified.
The ATTACKMODE command consists of these parts
The ATTACKMODE keyword
The mode, or modes
HID or STORAGE or HID STORAGE or OFF
Optionally a VID and PID
Optionally a MAN, PROD and SERIAL
As the comment suggests, the USB Rubber Ducky will be recognized by the target as a benign USB flash drive.
As the comment suggests, the USB Rubber Ducky will be recognized by the target as a USB Human Interface Device (HID) "keyboard".
As the comment suggests, the USB Rubber Ducky will not be recognized by the target.
If no ATTACKMODE command is specified as the first command (excluding REM), the new USB Rubber Ducky will default to the original standard HID mode and function as a keyboard.
Duplicate or redundant ATTACKMODE commands will be ignored. For example, if the ATTACKMODE is currently STORAGE and a new ATTACKMODE STORAGE command is specified, it will be ignored and the USB Rubber Ducky will not be re-enumerated by the target.
If no BUTTON_DEF is implemented, pressing the button will execute ATTACKMODE STORAGE — switching the USB Rubber Ducky into a flash drive.
If no inject.bin file is found on the root of the MicroSD card (the USB Rubber Ducky storage), then the device will show a red LED and execute ATTACKMODE STORAGE.
Multiple modes may be specified simultaneously. When this is done, the USB Rubber Ducky device is recognized as what's called "composite device", whereby multiple functions may be defined.
For example, the USB Rubber Ducky can act as both a HID keyboard, and a "flash drive" STORAGE device.
As the comment suggests, the USB Rubber Ducky will be recognized by the target as a composite device with both the HID "keyboard" and STORAGE functions.
The order in which the ATTACKMODE parameters STORAGE and HID does not matter.
The ATTACKMODE command may be used multiple times throughout a payload.
Changing the attack mode will cause the target to re-enumerate the device.
This payload will begin by enumerating as a HID keyboard.
The USB Rubber Ducky will then enumerate as a mass storage "flash drive" for 30 seconds.
Once more it will be enumerated as only a HID keyboard.
Next it will enumerate as both a HID keyboard and a mass storage "flash drive".
Finally, the device will seem to be disconnected.
USB devices identify themselves by combinations of Vendor ID and Product ID. These 16-bit IDs are specified in hex and are used by the target to find drivers (if necessary) for the specified device.
On a Linux system, the VID and PID for each connected USB device can be shown using the lsusb (list USB) command.
In the above screenshot, we can see that the device with Vendor ID 046D and Product ID c31c is connected to the computer. In this example, the vendor is Logitech, Inc. and the Product is Keyboard K120.
Using the ATTACKMODE command, the optional VID and PID parameters may be specified using the following syntax:
This ATTACKMODE command will instruct the USB Rubber Ducky to enumerate using the defined values, thus spoofing a real Logitech K120 keyboard. This can be very useful in situations where the target is configured to only allow interaction with specific devices.
A nearly complete list of VID and PID information may be found from Linux USB Project website at http://www.linux-usb.org/usb.ids
Checking this list, we can see that Apple uses the Vendor ID 05AC. Among others, we find that the Product ID 021E specifies the Aluminum Mini Keyboard (ISO). This is very useful when deploying payloads against macOS targets as a non-Apple keyboard will result in the Keyboard Setup Assistant opening.
If the following ATTACKMODE is specified, the Keyboard Setup Assistant will be suppressed.
In addition to the Vendor ID and Product ID parameters used to identify a USB device, the device iManufacturer (MAN), iProduct (PROD) and iSerial (SERIAL) may be specified using ATTACKMODE.
When using the MAN, PROD and SERIAL parameters, all three must be specified.
Checking lsusb (List USB) with the -v (verbose) option, we can see that the specified device includes the VID and PID values of the Apple, Inc. Aluminum Mini Keyboard (ISO), however the MAN, PROD and SERIAL values are defined as specified using the ATTACKMODE command.
If no MAN, PROD and SERIAL parameters are specified, the USB Rubber Ducky will enumerate with the defaults "USB Input Device" (for both MAN and PROD) and a SERIAL of 111111111111.
Keeping in mind that the ATTACKMODE command may be executed multiple times within a payload, and that device enumeration is dependant on the identifiers specified within the ATTACKMODE command (VID, PID, MAN, PROD and SERIAL), re-enumerating the device may only require changing one value — depending on the target OS. This may be useful when re-enumeration is desired.
If specified, the SERIAL_RANDOM parameter will use the pseudorandom number generator to select a unique 12 digit serial number. This is covered in greater detail in the section on randomization.
Within a payload the ATTACKMODE command may be executed multiple times.
In some situations it can be useful to "remember" an ATTACKMODE state, for later recall.
The SAVE_ATTACKMODE command will save the currently running ATTACKMODE state (including any specified VID, PID, MAN, PROD and SERIAL parameters) such that it may be later restored.
The parameters HID of the command ATTACKMODE will be saved for later recall.
The RESTORE_ATTACKMODE command will restore a previously saved ATTACKMODE state.
The USB Rubber Ducky will be recognized as a composite USB device with both HID and STORAGE features.
Strings will be typed informing the user of the save state, the button functionality, and entering ATTACKMODE OFF.
Pressing the button will restore the previously initialized ATTACKMODE.
The following internal variables relate to ATTACKMODE and may be used in your payload for advanced functions.
Returns the currently operating Vendor ID with endian swapped.
May only be retrieved. Cannot be set.
Returns the currently operating Product ID with endian swapped.
May only be retrieved. Cannot be set.
Returns the currently operating ATTACKMODE represented as:
May only be retrieved. Cannot be set.
| Parameter | Description | Accepted Value |
|---|---|---|
| Parameter | Description | Accepted Value |
|---|---|---|
| Value | ATTACKMODE |
|---|---|
HID
HID – Human Interface Device. Emulates a Keyboard for Keystroke Injection.
STORAGE
MSC – USB Mass Storage Emulates a Flash Drive for working with files.
OFF
Disables device enumeration by the target.
VID_
Vendor ID
16 bits in HEX
PID_
Product ID
16 bits in HEX
MAN_
iManufacturer
16 alphanumeric characters
PROD_
iProduct
16 alphanumeric characters
SERIAL_
iSerial
12 digits
0
OFF
1
HID
2
STORAGE
3
COMPOSITE (Both HID and STORAGE)
lsusb command from a Linux system showing the USB Rubber Ducky with MAN, PROD and SN specified.