I. Introduction
The growing issue of cyber security and its impact on Industrial Control Systems (ICS) highlights fundamental risks to the national critical infrastructure. Although the attacks targeted IT infrastructure, their consequences also affected operational technology used for production. The data that proves it is gathered from Supervisory Control And Data Acquisition (SCADA) servers; data storage servers (Historian); data gateways according Open Platform Communication (OPC) standard; stationary and mobile workstations of engineers and operators; Human Machine Interface (HMI). The statistics analyzed also include data received from computers of industrial control network administrators and software developers who develop software for industrial automation systems [1]. The ICS cyber security landscape goes complicated after synergy with IoT. Both parties have specific disadvantages concerning cyber security [2]–[4].