In the work, a cyber security logical and probabilistic model of a critical infrastructure facility in the energy sector was developed and investigated. The cyber security logical and probabilistic model describes the development of adverse events that arise in the Industrial Control System of the electrical network from the realization of possible threats from cyberspace, such as attacks on the protection system through the corporate network, connection through a modem and wireless connection. The resulting model is based on sequentially developed structural, logical and probabilistic models. The field of use of the developed model is automation systems for designing information protection systems or designing trajectories of attacks on these systems. The model was also applied to study the sensitivity of the probability of the development of adverse events to variations in the probability of realization of possible threats to the system.