Critical infrastructures are always a potential target for cyberattacks, as they control and allow access to the major infrastructure services of a nation. The repercussions of a successful attack on these systems can be catastrophic. One of the critical infra-structures of a country is the Industrial Control Systems (ICSs), used to automate and control vital functions of the various industrial infrastructures.

This work aims to identify the ICSs exposed to the Internet in Portugal and investigate their level of risk in terms of security. To achieve that objective, a methodology to identify the exposed ICSs on the Internet in Portugal and their level of risk was developed. The proposed methodology implied the identification of the ICSs, the calculation of their risk level according to their characteristics, and the development of a data warehouse to combine and organize the data into one comprehensive database, as well as, to enable the easy analysis of it. The results of this work allow the industry and all organizations that have ICSs to be aware of how exposed and vulnerable their systems are, enabling them to devote more attention to the systems that may be at risk of a cyberattack and mitigate their vulnerabilities.