INTERCEPT

Signal Intelligence

A sleek, modern web-based front-end for signal intelligence tools.
Unified interface for pager decoding, 433MHz sensors, WiFi reconnaissance, and Bluetooth scanning.

Screenshot

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What is INTERCEPT?

INTERCEPT is a web-based front-end that provides a unified, modern interface for signal intelligence tools:

• rtl_fm + multimon-ng - For decoding POCSAG and FLEX pager signals
• rtl_433 - For decoding 433MHz ISM band devices (weather stations, sensors, etc.)
• aircrack-ng / kismet - For WiFi reconnaissance and network analysis
• hcitool / bluetoothctl / ubertooth - For Bluetooth device scanning and tracking

Instead of running command-line tools manually, INTERCEPT handles the process management, output parsing, and presents decoded data in a clean, real-time web interface.

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Features

Pager Decoding

• Real-time decoding of POCSAG (512/1200/2400) and FLEX protocols
• Customizable frequency presets stored in browser
• Auto-restart on frequency change while decoding

433MHz Sensor Decoding

• 200+ device protocols supported via rtl_433
• Weather stations - temperature, humidity, wind, rain
• TPMS - Tire pressure monitoring sensors
• Doorbells, remotes, and IoT devices
• Smart meters and utility monitors

WiFi Reconnaissance

• Monitor mode management via airmon-ng
• Network scanning with airodump-ng or Kismet
• Channel hopping or fixed channel monitoring
• Deauthentication attacks for authorized testing
• Handshake capture for WPA/WPA2 networks
• Channel utilization visualization (2.4GHz)
• Security overview chart (WPA3/WPA2/WEP/Open)
• Real-time radar display of nearby networks

Bluetooth Scanning

• BLE and Classic Bluetooth device scanning
• Multiple scan modes - hcitool, bluetoothctl, Ubertooth, Bettercap
• Tracker detection - AirTag, Tile, Samsung SmartTag, Chipolo
• Device classification - phones, audio, wearables, computers
• Manufacturer lookup via OUI database
• Service enumeration via SDP
• L2CAP ping for device reachability
• Proximity radar visualization
• Device type breakdown chart

General

• Web-based interface - no desktop app needed
• Live message streaming via Server-Sent Events (SSE)
• Audio alerts with mute toggle
• Message export to CSV/JSON
• Signal activity meter and waterfall display
• Message logging to file with timestamps
• RTL-SDR device detection and selection
• Configurable gain and PPM correction
• Device intelligence dashboard with tracking
• Disclaimer acceptance on first use
• Auto-stop when switching between modes

Requirements

Hardware

• RTL-SDR compatible dongle (RTL2832U based)

Software

• Python 3.7+
• Flask
• rtl-sdr tools (rtl_fm)
• multimon-ng (for pager decoding)
• rtl_433 (for 433MHz sensor decoding)
• aircrack-ng (for WiFi reconnaissance)
• kismet (optional, alternative WiFi scanner)
• BlueZ tools - hcitool, bluetoothctl, sdptool, l2ping (for Bluetooth)
• Ubertooth tools (optional, for advanced BLE sniffing)
• Bettercap (optional, alternative BLE scanner)

Installation

1. Install RTL-SDR tools

macOS (Homebrew):

brew install rtl-sdr

Ubuntu/Debian:

sudo apt-get install rtl-sdr

Arch Linux:

sudo pacman -S rtl-sdr

2. Install multimon-ng

macOS (Homebrew):

brew install multimon-ng

Ubuntu/Debian:

sudo apt-get install multimon-ng

From source:

git clone https://github.com/EliasOenal/multimon-ng.git
cd multimon-ng
mkdir build && cd build
cmake ..
make
sudo make install

3. Install rtl_433 (optional, for 433MHz sensors)

macOS (Homebrew):

brew install rtl_433

Ubuntu/Debian:

sudo apt-get install rtl-433

From source:

git clone https://github.com/merbanan/rtl_433.git
cd rtl_433
mkdir build && cd build
cmake ..
make
sudo make install

4. Install aircrack-ng (optional, for WiFi)

macOS (Homebrew):

brew install aircrack-ng

Ubuntu/Debian:

sudo apt-get install aircrack-ng

5. Install Bluetooth tools (optional)

Ubuntu/Debian:

sudo apt-get install bluez bluetooth

macOS: Bluetooth tools are built-in, though with limited functionality compared to Linux.

6. Install Python dependencies

pip install -r requirements.txt

7. Clone and run

git clone https://github.com/yourusername/intercept.git
cd intercept
python3 intercept.py

Open your browser to http://localhost:5050

Usage

1. Select Device - Choose your RTL-SDR device from the dropdown
2. Set Frequency - Enter a frequency in MHz or use a preset
3. Choose Protocols - Select which protocols to decode (POCSAG/FLEX)
4. Adjust Settings - Set gain, squelch, and PPM correction as needed
5. Start Decoding - Click the green "Start Decoding" button
6. View Messages - Decoded messages appear in real-time in the output panel

Frequency Presets

• Click a preset button to quickly set a frequency
• Add custom presets using the input field and "Add" button
• Right-click a preset to remove it
• Click "Reset to Defaults" to restore default frequencies

Message Logging

Enable logging in the Logging section to save decoded messages to a file. Messages are saved with timestamp, protocol, address, and content.

Default Frequencies

Pager (UK)

• 153.350 MHz - UK pager frequency
• 153.025 MHz - UK pager frequency

433MHz Sensors

• 433.92 MHz - EU/UK ISM band (most common)
• 315.00 MHz - US ISM band
• 868.00 MHz - EU ISM band
• 915.00 MHz - US ISM band

You can customize pager presets in the web interface.

API Endpoints

Pager & Sensor

Endpoint	Method	Description
/	GET	Main web interface
/devices	GET	List RTL-SDR devices
/start	POST	Start pager decoding
/stop	POST	Stop pager decoding
/start_sensor	POST	Start 433MHz sensor listening
/stop_sensor	POST	Stop 433MHz sensor listening
/status	GET	Get decoder status
/stream	GET	SSE stream for pager messages
/stream_sensor	GET	SSE stream for sensor data
/logging	POST	Toggle message logging
/killall	POST	Kill all decoder processes

WiFi

Endpoint	Method	Description
/wifi/interfaces	GET	List WiFi interfaces and tools
/wifi/monitor	POST	Enable/disable monitor mode
/wifi/scan/start	POST	Start WiFi scanning
/wifi/scan/stop	POST	Stop WiFi scanning
/wifi/deauth	POST	Send deauthentication packets
/wifi/networks	GET	Get discovered networks
/wifi/stream	GET	SSE stream for WiFi events

Bluetooth

Endpoint	Method	Description
/bt/interfaces	GET	List Bluetooth interfaces and tools
/bt/scan/start	POST	Start Bluetooth scanning
/bt/scan/stop	POST	Stop Bluetooth scanning
/bt/enum	POST	Enumerate device services
/bt/ping	POST	L2CAP ping a device
/bt/devices	GET	Get discovered devices
/bt/stream	GET	SSE stream for Bluetooth events

Troubleshooting

No devices found

• Ensure your RTL-SDR is plugged in
• Check rtl_test works from command line
• On Linux, you may need to blacklist the DVB-T driver

No messages appearing

• Verify the frequency is correct for your area
• Adjust the gain (try 30-40 dB)
• Check that pager services are active in your area
• Ensure antenna is connected

Device busy error

• Click "Kill All Processes" to stop any stale processes
• Unplug and replug the RTL-SDR device

License

MIT License - see LICENSE for details.

Author

Created by smittix - GitHub

Acknowledgments

• rtl-sdr - RTL-SDR drivers
• multimon-ng - Multi-protocol pager decoder
• rtl_433 - 433MHz sensor decoder
• aircrack-ng - WiFi security auditing tools
• Kismet - Wireless network detector and sniffer
• BlueZ - Official Linux Bluetooth protocol stack
• Ubertooth - Open source Bluetooth research tool
• Bettercap - Network reconnaissance and MITM framework
• Inspired by the SpaceX mission control aesthetic

⚠️ Disclaimer

This software is for educational purposes only and intended for use by cybersecurity professionals in controlled environments.

By using INTERCEPT, you acknowledge that:

• You will only use this tool with proper authorization
• Intercepting communications without consent may be illegal in your jurisdiction
• WiFi deauthentication and Bluetooth attacks should only be performed on networks/devices you own or have explicit permission to test
• You are solely responsible for ensuring compliance with all applicable laws and regulations
• The developers assume no liability for misuse of this software

A disclaimer must be accepted when first launching the application.