This is a simple plugin for Ettercap which exploits the lack of data integrity in control systems protocols.
This Ettercap plugin performs a MITM attack against Modbus systems. It records modbus communication for ten seconds, and then overwrites future status data on a control system network with previously-recorded responses. This effectively blinds a control system operator to the status of their process, while leading the operator to believe that status updates are still occuring.
It is meant to demonstrate a decades-old issue with process control systems that has never been addressed by vendors nor by operators. My hope is that this will increase public dialogue about replacing control systems protocols which lack data integrity, especially in critical infrastructure.
To compile this plugin, you will want to check out the current version of ettercap from git (it contains patches necessary for this plugin to work), place the modbus_vcr.c file into the ettercap plugins directory, and modify the plugins configuration file so that building ettercap will also build the plugin.
Please use this tool for demonstration purposes only, and only on non-critical systems.