The paper proposes a model for determining actual threats to the information security of distributed information systems, based on algorithms of fuzzy inference and the theory of fuzzy neural systems, unlike known ones, uses sufficient and necessary indicators, excludes expert errors, increases the detection of the number of actual threats to information security of distributed systems by 5 %, reduces the cost of purchasing information protection equipment from 15 to 30%. It takes into account the following factors: the IT infrastructure of the distributed information system, the capabilities of attackers and their level of motivation in the distributed information system, the list of existing protection tools in the distributed information system.
 The proposed approach differs from existing ones in the following: lack of involvement of highly qualified specialists in the field of information security; the process is automated, has a low computational complexity; absence of deficiencies in expert assessments; allows you to determine the list of current information security threats in information systems of various classes and types.
 The task of ensuring the security of confidential information becomes the most urgent, which is due to the growth of computer attacks and leaks of information, which are reflected in the statistical data on the commission of crimes in the field of high technologies, the growth of criminal activity using modern communication devices and the Internet.
 Existing methods of modeling current threats to information security and assessing the effectiveness of the information protection system cannot be used at all stages of the life cycle of distributed information systems - they do not take into account the following indicators in the complex: IT infrastructure of distributed information systems, current threats to information security, security requirements for confidential information, a list of means of protecting confidential information and their value as important indicators when solving these problems.
 In order to achieve the goals of ensuring the security of confidential information, it is necessary to: organize the effective creation of an information protection system (information security system), effective modeling (identification of the list) of current threats to information security, identification of the current violator, and also provide the opportunity to conduct a qualitative assessment of the effectiveness of the information security (protection) system.
 One of the most important tasks of ensuring the security of confidential information is the assessment of the effectiveness of the protection (security) system. In this regard, the goal of the work (research) is to improve the quality of the evaluation of the effectiveness of the protection (security) systems of distributed information systems by determining sufficient and necessary evaluation indicators using modern (promising) information technologies that allow the most effective solution of the following tasks: determination operating parameters of adaptive production fuzzy neural systems, which are most suitable for solving the tasks, application of Data Science technologies in data processing, fuzzy output algorithms.