Overview

At its core, this project leverages the ESP32-C3’s Wi-Fi hardware to craft covert communication channels by embedding encrypted messages inside 802.11 management frames. Unlike typical Wi-Fi data packets, these frames are less likely to raise suspicion on a monitored network since they don’t follow the usual network traffic patterns.

Paired with a Python listener script (SubrosaServer.py), you get a complete system for stealth message transmission and reception that doesn’t rely on connecting to any Wi-Fi network.

Stealthy Wi-Fi Message Dropping with ESP32-C3

In the world of wireless security and covert communication, stealth is king. Today, I’m excited to share a new open-source project: ESP32c3StealthDropper — a stealthy, encrypted message dropper built on the ESP32-C3 microcontroller that uses custom Wi-Fi management frames to send and receive hidden messages.

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Why Does This Matter?

Here’s why this technique is useful:

Covert communications: Communicate secretly without appearing as a connected device on a network.
Penetration testing: Help red teams demonstrate real stealth wireless attack vectors.
Data exfiltration: Extract data covertly in hostile network environments.
Stealth IoT networks: Create low-profile sensor networks communicating below the radar.

How Does It Work?

The ESP32-C3 runs a custom firmware (listener.c) that sends and listens for these custom Wi-Fi frames. The frames carry encrypted payloads that the Python listener decodes and presents in human-readable form.

This unique approach bypasses many traditional Wi-Fi monitoring techniques and showcases the flexibility and power of the ESP32-C3’s wireless stack. Getting Started

Want to try it yourself? Here’s a quick overview: Requirements

ESP32-C3 dev board
ESP-IDF v4.4+
Python 3 with scapy and argparse

Build and Flash the Firmware


root💀NullOrigin:~# idf.py set-target esp32c3
root💀NullOrigin:~# idf.py menuconfig
root💀NullOrigin:~# idf.py build
root💀NullOrigin:~# idf.py -p (YOUR_SERIAL_PORT) flash
root💀NullOrigin:~# idf.py -p (YOUR_SERIAL_PORT) monitor

Run the Python Listener


root💀NullOrigin:~# pip install scapy argparse
root💀NullOrigin:~# python SubrosaServer.py

The listener will start decoding incoming stealth messages for you to read and process. Explore the Code

listener.c — Firmware handling stealth transmission/reception
SubrosaServer.py — Python listener and decoder
ReadMe.md — Full documentation and instructions

Check out the full source and instructions on GitHub: ESP32c3StealthDropper Repository: https://github.com/aMiscreant/ESP32c3StealthDropper