# Making a $2 BadUSB (USB Rubber Ducky)

## What is a BadUSB?
A BadUSB is a USB device that acts as a keyboard and injects preprogrammed keystrokes into a computer. A BadUSB is Indistinguishable from a generic keyboard, making it near impossible to detect and patch. You can setup reverse shells, change the desktop background or change settings. The opportunities are limitless. 

## What do you need?
Depending on where you get a BadUSB from; you can expect a range of prices between $2 to $45.

The Hak5 USB Rubber Ducky costs around $45.
![image.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1659330336191/cNLNKbEj0.png align="left")

Where are ATMEGA32U4 cost around $30 from Amazon.
![image.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1659331323067/Rs7jP2K4K.png align="left")
If you get an ATTINY85 Arduino board you can expect around $2-10. This board is the one I recommend for beginners. You can get it anywhere from platforms like eBay, Alibaba or AliExpress. One thing to note about this board is that it has a 5-second delay before inputting keystrokes. This is due to it checking if it needs to be written to.
![image.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1659330178553/Pizub-EdR.png align="left")

This tutorial is for an ATTINY85. This is due to its cheapness and availability. You will need the following:
1. Arduino ATTINY85 
2. Arduino IDE
3. 20 minutes of free time

## Tutorial

### 1. Install the Arduino IDE

Download and install the [Arduino IDE](https://www.arduino.cc/en/software).


### 2. Install the Digispark drivers
You are required to download [Digispark drivers](https://github.com/digistump/DigistumpArduino/releases/download/1.6.7/Digistump.Drivers.zip) if your Arduino version is Arduino 1.6.6 or higher.

Unzip and install the file DPInst64.exe

### 3. Add the Digispark Board Support Package

Open up the Arduino IDE

Open up Files ---> Preferences

Add the below text to the "Additional Boards Managers URLs:"
```
http://digistump.com/package_digistump_index.json
```


![image.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1662588867084/y3EcWtDMW.png align="left")



### 4. Add the Digispark Board
Open up Tools ---> Board ---> Board Manager

![image.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1662588723692/7jCI9x---.png align="left")

Search up Digispark and click on the install button.

![image.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1662588767771/gTQmG5lLA.png align="left")




### 5. Create scripts

If you don't want to create any of your own scripts, their is a whole github reposistory dedicated to premade scripts. You can find it [here](https://cedarctic.github.io/digiQuack/). 


If you want to create an scripts, I recommend using Ducky Script and then converting it to Arduino code using d4n5h's Ducky to Arduino [converter](https://d4n5h.github.io/Duckuino/). It is far simpler then writing it directly in Arduino code. You can find the syntax of Ducky script here.

Below is an example of converting Ducky Script to Arduino code.

Note: There is a problem with the converter where ```DigiKeyboard.sendKeyStroke(0, MOD_GUI_LEFT, KEY_R);``` should be ```DigiKeyboard.sendKeyStroke(MOD_GUI_LEFT, KEY_R)```

### 6. Upload your script
Click on the upload button.

![image.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1662590767233/dC6G2l5UV.png align="left")
When the console says "plug in the device now", insert your ATTINY85 into your USB port.

![image.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1662591129655/El9XCiMvK.png align="left")


## Ending Notes
I hope you enjoyed this article about the ATTINY85. If you have any questions you can always leave a comment below or feel free to reach out to me on Twitter at @dingo418.


## Sources
[$1 BadUSB - DigiSpark Drive By HID Tutorial](https://www.youtube.com/watch?v=fGmGBa-4cYQ&ab_channel=Seytonic)

[Run USB Rubber Ducky Scripts on a Super Inexpensive Digispark Board](https://null-byte.wonderhowto.com/how-to/run-usb-rubber-ducky-scripts-super-inexpensive-digispark-board-0198484/)