BJORN : Network Scanning Tool on Raspberry Pi

1. Project Overview

This project involves building BJORN, a network scanning and offensive security tool, on a Raspberry Pi Zero 2 W with a Waveshare 2.13-inch e-Paper HAT. BJORN autonomously scans networks to identify open ports, exposed services, and vulnerabilities, supporting features like brute force attacks and custom scripts in a portable, Tamagotchi-like device.

Objective: Create a compact pentesting device for network security testing.
Hardware Used: Raspberry Pi Zero 2 W, Waveshare 2.13-inch e-Paper HAT, Class 10 MicroSD card.
Software Used: BJORN software, Python, Raspberry Pi OS Lite (32-bit, Debian Bookworm).
Skills Learned: Raspberry Pi configuration, Python dependency management, e-Paper display setup.

Amazon Link for Hardware used

2. Resources and References

The following resources were essential for setting up BJORN:

Resource 1:
Title: Bjorn - The Cyber Viking - Installation and Demo
Usage: Provided a visual guide for hardware assembly and running the automated installation script.
Resource 2:
Title: BJORN GitHub Repository
Usage: Supplied the official installation script and documentation for software configuration and troubleshooting.

Additional Notes: The YouTube video offered practical setup visuals, while the GitHub README provided detailed command-line instructions, making them complementary resources.

3. Steps Taken

The step-by-step process to build and deploy BJORN is outlined below:

Step 1: Hardware Assembly
Description: Connected the Waveshare 2.13-inch e-Paper HAT to the Raspberry Pi Zero 2 W using GPIO pins.
Challenges: Ensured correct pin alignment and avoided pushing pins too far into the e-Paper HAT to prevent damage.
Step 2: OS Installation
Description: Flashed Raspberry Pi OS Lite (32-bit, Debian Bookworm) onto a Class 10 MicroSD card using Raspberry Pi Imager. Configured settings in Imager: set hostname to "bjorn," defined username and password, and added Wi-Fi credentials (SSID and password) for automatic LAN connectivity.
Challenges: Verified OS compatibility and ensured Wi-Fi settings were correctly applied to enable SSH access in the next step.
Step 3: BJORN Software Installation
Description: Identified the Pi’s IP address on the Wi-Fi network, then used SSH (with the username and password set in Step 2) to connect. Executed commands to download and run the automated installation script (install_bjorn.sh) from the GitHub repository, which installed dependencies and BJORN software.
Challenges: Confirmed stable network connectivity before running the script to avoid interruptions.
Step 4: Configuration and Testing
Description: Configured the e-Paper display by selecting screen version 3 in shared_config.json during installation. Ran the full installation, rebooted, and validated setup by accessing the web UI at [Pi’s IP]:8000 in a browser on the same Wi-Fi network. Tested BJORN’s network scanning on a local network.
Challenges: Adjusted SPI settings to stabilize the e-Paper display output.

5. Tips and Lessons Learned

Practical advice and insights gained from the project:

Tip 1: Use a Class 10 MicroSD card to ensure reliable performance during installation and operation.
Tip 2: Configure Wi-Fi and hostname settings in Raspberry Pi Imager before flashing to enable automatic LAN connectivity.
Tip 3: Select the correct e-Paper screen version (e.g., version 3) during installation to avoid display issues.
Tip 4: Access the web UI at [Pi’s IP]:8000 while on the same Wi-Fi network to validate setup.
Lesson Learned: Precise configuration of the e-Paper HAT is critical to prevent display errors.
Future Improvements: Add an external antenna to improve Wi-Fi range for broader network scanning.

6. Conclusion

BJORN was successfully set up and tested, autonomously scanning a local network and displaying results on the e-Paper HAT and web interface. This project enhanced my understanding of Raspberry Pi-based pentesting tools and network security. Future plans include exploring custom attack scripts to expand BJORN’s functionality.

7. Additional Notes

The YouTube video was invaluable for visualizing the hardware assembly process.
The GitHub repository’s TROUBLESHOOTING.md file helped resolve SPI-related display errors.