Combined cyber and physical attacks on Critical Infrastructures have disastrous consequences on economies and in social well-being. Protection and resilience of CIs under combined attacks is challenging due to their complexity, reliance on ICT systems and the interdependences between different types of CIs. The PRAETORIAN framework was designed to address these challenges, by integrating components responsible for detecting both cyber and physical threats. Additionally, it forecasts how the combined attacks will evolve and their cascading effects on interdependent CIs. The PRAETORIAN framework was demonstrated based on a realistic scenario in the Zagreb airport, combining both physical and cyber attacks.

In this paper, we describe the functioning of the PRAETORIAN Framework, an integrated platform to identify complex threats across the physical and cyber domains of Critical Infrastructures (CIs). Therefore, the framework combines a physical and a cyber situation awareness solution into an innovative Hybrid Situation Awareness tool to detect the different stages of a complex threat. Further, the framework supports the decision makers and emergency organizations with a Coordinated Response tool to align and plan the activities for reducing or preventing the effects of an attack. All aspects are described according to a real-life use case that has been tested at the Zagreb airport.