Cyber attacks on critical infrastructure's objects can have dire consequences, as our entire lives depend on the working capacity of such systems. In Ukraine, cybercrime provides for criminal and civil liability under the Criminal and Civil Codes of Ukraine, and under the Law of Ukraine “On the Fundamental Principles of Cyber Security in Ukraine”. A successfully implemented decision-making support system that can provide a conclusion of legal responsibility in the cybersecurity domain, namely, propose sanctions recommended in the case of an offence or multiple offences, can significantly improve the productivity of the Ukrainian cyber police. This paper explores the legal and organizational princi-ples of cybersecurity in today's information society, and first time develops the method and production rules of forming a logical conclusion about legal responsibility in the cybersecurity domain, that are used to form the conclusion about legal responsibility, namely for the selection of a sanction or set of sanctions recommended in the event of a particular offence or multiple cyber-security offences.