When exploring the world of Industrial Control Systems security, one quickly realizes that the tooling landscape is quite different from what we are used to in traditional IT penetration testing. Protocols like Modbus TCP are still heavily used in many environments, and understanding how to interact with them is crucial for both defenders and security researchers.
To practice these skills in a safe environment, I often turn to training platforms such as:
Why I Built Modbuzz
While working through ICS-focused labs, I wanted a lightweight tool to interact with Modbus TCP registers directly from the command line. Instead of relying on heavy frameworks, I decided to write my own small Python script – and that’s how Modbuzz was born.
Modbuzz allows you to:
- Read holding registers from a target Modbus TCP server.
- Write values (
0or1) to specific registers. - Repeat operations multiple times to observe changes or test system behavior.
- Use a simple interactive menu for quick experimentation.
How It Works
The tool is built on top of the pyModbusTCP library and runs as a straightforward CLI program. Once launched with the target IP address, Modbuzz presents a menu where you can choose whether to read or write registers.
python3 modbuzz.py 192.168.2.1
This makes it easy to experiment during labs like Attacking ICS, LabShock, or Alchemy without needing complex tooling.
Use Cases in Training Labs
In ICS security training environments, Modbuzz can be used to:
- Interact with simulated PLCs.
- Observe how registers change during process operations.
- Test writing values to understand potential attack impacts (all in a safe, controlled lab).
Important Note
This tool is designed for educational and testing purposes only.
Please do not use it against production systems or networks you do not own or have explicit authorization to test.
Closing Thoughts
Building Modbuzz was a fun way to combine Python scripting with ICS protocol exploration. It also became a handy utility for lab work while strengthening my understanding of Modbus TCP.
If you’re diving into ICS security, I highly recommend checking out:
