Recently I was asked “How could a hacker possibly attack an industrial controller like a PLC or SIS, since there is no operating system in these devices?”
Now some manufacturers would like people to believe there is no operating system in a controller, but unfortunately this is not true. Every RTU, PLC, SIS or DCS controller on the market today has a commercial operating system in it. For example, here are just a few I have worked directly with in the past: