Information exchange is one of the essential processes in any social system. Contemporary channels of social communication and, primarily, the global information space (the Internet) and its social media are actively used to organize a range of activities which have an information and psychological impact on individual personality, social groups, and society as a whole. A well-known negative aspect of this practice is propaganda of extremist ideologies, terrorism, and other kinds of illegal activities. It is necessary to understand the nature of the information dissemination process in order to plan and carry out actions related to information management, as well as to identify and counteract destructive actions. This paper aims to develop a technique and model which would make it possible to study the patterns of information interaction in social systems. The paper presents a mathematical model for the information interaction process based on the theory of cellular automata and fuzzy cognitive modeling that makes it possible to formalize and consider the subjective qualities of communicators, the evaluation of which is given verbally. Taking into account the specifics of largescale social systems and the complexity of obtaining and processing initial data for modeling them, a supplement to the model was suggested using representative sample data and statistical parameter distribution. Numerical experiments were performed to determine analytical dependencies between the parameters of the social system (connectivity, sensibility, sociability) and the dynamics of changes in opinions of agents in relation to the disseminated information.