Sigint

The idea is to build a small device (Raspberry Pi 3 in my case) that will scan WiFi probes, Bluetooth devices and IMSI numbers (still work in progress) nearby, and log those into a server.

This have different purposes. My original idea is to use it as an (potential) intruder monitoring system for off-grid properties.

How it works

Server & Stations.

Requirements

This project was tested on:

• Raspberry Pi 3 B+ with Kali linux 2020
• Raspberry Pi 4 B with Raspberry Pi OS

Software

Linux Packages

sudo apt-get install -y bluez wireless-tools tcpdump tshark

Python dependencies

cd scripts; pip install -r requirements.txt

IMSI Catcher

https://github.com/Oros42/IMSI-catcher

For installing it under Raspberry Pi follow this script / guide: https://gist.github.com/arall/370b5fe5277506026c078a7cf5cb97e3

Get your device info with: *#*#4636#*#*

Laravel Nova License

The admin panel works with Laravel Nova and requires a commercial license. You can still use the project without an admin GUI by querying the MySQL DB or by implementing any other Laravel Admin panel.

If you want to remove Laravel Nova, remove it from composer.json before the setup.

Hardware

WiFi device with monitor mode

Raspberry Pi onboard Wi-Fi adapter doesn't support monitor mode out of the box. Any external USB WiFi cards that support monitor mode should work with additional drivers. I've tested it with Alfa AWUSO36NH and AWUS036NHA in a Raspberry Pi 4.

Source: https://www.intuitibits.com/2021/02/17/using-a-raspberry-pi-4-as-a-remote-sensor-for-wifi-explorer-pro-and-airtool

sudo apt update
sudo apt install raspberrypi-kernel-headers
sudo reboot
git clone https://github.com/aircrack-ng/rtl8812au
cd rtl8812au

For RPI 1/2/3/ & 0/Zero:

sed -i 's/CONFIG_PLATFORM_I386_PC = y/CONFIG_PLATFORM_I386_PC = n/g' Makefile
sed -i 's/CONFIG_PLATFORM_ARM_RPI = n/CONFIG_PLATFORM_ARM_RPI = y/g' Makefile

For RPI 3B+ & 4B you will need to run those below which builds the ARM64 arch driver:

sed -i 's/CONFIG_PLATFORM_I386_PC = y/CONFIG_PLATFORM_I386_PC = n/g' Makefile
sed -i 's/CONFIG_PLATFORM_ARM64_RPI = n/CONFIG_PLATFORM_ARM64_RPI = y/g' Makefile

make
sudo make install

Bluetooth device

Built in Raspberry Pi bluetooth works out of the box.

SDR device

USB DVB-T key (RTL2832U) with antenna (less than 15$) or a OsmocomBB phone or HackRF.

Setup

Server

Copy the .env.example into .env and set the variables to connect to the database, as well as your Nova License and Docker settings (in case you want to use those).

Docker

Build and start the container:

docker compose up -d

Prompt a bash into the docker container:

docker exec -it sigint-app-1 bash

Then follow the non-docker setup.

Non-Docker

For the server, install using Composer:

composer install

Generate a Laravel application key:

php artisan key:generate

And then run the database migrations and seeders:

php artisan migrate --seed

If you're using Laravel Nova, you can create a web user with:

php artisan nova:user

Then you will be able to login using the web panel at http://127.0.0.1/nova.

Stations

First create your station in the DB. If using Nova, you can do that using the web panel. Otherwise you can manually create that directly from the DB. Each station have a token that will be used as authentication for the API calls.

The monitoring scripts are located in scripts/ directory.

First, set the server API_URL (for example http://127.0.0.1/api/) and the API_KEY (the station token) in scripts/.env.

WiFi

Start monitor mode on your WiFi device: sudo airmon-ng start wlan1 (requires aircrack-ng) or sudo iw phy phy2 interface add wlan1mon type monitor; sudo ifconfig wlan1mon up.

List the wifi interfaces with sudo iwconfig.

Run the script in a background session (or as a daemons), change the interface if needed:

cd scripts
sudo python3 wifi.py wlan1mon

Bluetooth

Make sure the Bluetooth service is enabled: sudo systemctl status bluetooth.service. If not, enable it with sudo systemctl enable bluetooth.service and sudo systemctl start bluetooth.service. List the Bluetooth interfaces with bt-adapter -i (requires bluez-tools).

Run the script in a background session (or as a daemons), change the interface if needed:

cd scripts
python3 bluetooth.py hci0

IMSI

To-do

Devices specs

https://www.raspberrypi.org/documentation/faqs/

Raspberry Pi 4 B
Power: 5V/3A
Consumption: 600mA
WiFi: 2.4 GHz and 5.0 GHz IEEE 802.11b/g/n/ac
BT: Bluetooth 5.0, BLE

Raspberry Pi 3 B+
Power: 5V/2.5A
Consumption: 500mA
WiFi: 2.4 GHz and 5.0 GHz IEEE 802.11.b/g/n/ac
BT: Bluetooth 4.2, BLE

Raspberry Pi Zero W
Power: 5V/1.2A
Consumption: 150mA
WiFi: 802.11 b/g/n wireless LAN
BT: Bluetooth 4.1, BLE

Limitations

The randomized MAC addresses being used are locally administered MAC addresses.
You can recognize a locally administered address by inspecting the 2nd least significant bit of the 2nd byte of the MAC address. http://www.dfrc.com.sg/mac-randomization-crowd-analytics/