Annotation: This paper presents a mathematical model for the spread of computer attacks on critical information infrastructure based on the extension of the basic Lotka-Volterra model. Within the framework of the proposed model, the problem to be solved is formulated, the point of stability of the system is determined, and a criterion is proposed for the adequacy of the applied methods for detecting attacks to changing parameters of the critical information infrastructure and existing cyber threats.

Keywords: Critical Information Infrastructure, Adequacy Criterion, Mathematical Model, Lotka-Volterra Model, Computer Attack Spread Rate, Stability Point, CII