Industrial Control Systems (ICS) and Supervisory control and data acquisition (SCADA) systems have lived in relative obscurity for decades. These devices and controllers use proprietary protocols in their build, software stacks, and communications protocols. Now they are using the same technology as your smart home controller or WiFi camera.
Industrial Control Systems (ICS) use the same technology as Internet of Things (IoT) devices and are susceptible to similar attack vectors as your DVR or WiFi Camera.
We see many legacy control systems connected to IP or Ethernet-based networks. In Europe, "Industry 4.0" is driving connectivity of the manufacturing floor. We see programmable logic controllers with Ethernet connections and old-school traffic control systems with IP-capability. There are clear business drivers for this "digital transformation" as connectivity and data analytics bring insights to drive down costs, improve efficiency and reduce downtime.
The industry is choosing cheap Systems-on-Chip (SOS)s over custom and expensive Application Specific Integrated Circuits (ASICs). These SoCs use embedded firmware, opening ICS devices up to the same attack vectors as consumer products:
ICS = IoT because industry is choosing SoCs and FPGAs with embedded firmware and OS instead of custom ASICs.