Rapid technological advances provide numerous benefits to our ways of work and leisure, banking and transportation, delivery of products and health assistance. The increased interconnectedness among devices, people, networks, and systems, however, introduces a level of complexity surpassing the experience accumulated so far. While the security of communications, network and information systems can be considered a well-established discipline, the study of security of cyber-physical systems is fairly recent. Furthermore, the dependencies of live organisms, including humans, with integrated sensors and electronics, of perceptions and cognition, and variety of drones on influences from cyberspace have been subject of only few, mostly incidental studies. The interdependencies among cyber, physical, biological systems, and humans in situation assessment and decision-making roles create new potential vectors of attack by malicious actors. If exploited, they will lead to cross impact among domains that are usually studied separately. Authors from three Bulgarian institutions, combining research and policy-making experience, embarked on the task to elaborate a comprehensive cybersecurity research agenda. This paper presents their concept for an integrative approach to the exploration of ‘systems of systems.’ The study is structured along five domains: communications and information systems and networks; cyber-physical system; bio-integrated systems; cognitive processes, i.e. the processes of shaping perceptions, assessing a certain situation and options and making decisions; and drones, remotely controlled or autonomous, the latter case being particularly reliant on advances in artificial intelligence. This paper outlines the problem of vulnerability of each of the five domains to influences from cyber space. Then it presents some advances in cross-domain understanding of vulnerabilities, supported by examples of cybersecurity studies, and provides the outlines of a corresponding, interdisciplinary research agenda, built around the concept of systems of systems. The authors conclude by predicting that the field of cybersecurity will be subject to considerable growth in coming years, requiring multi-and inter-disciplinary competencies and scientific support. © 2019, Curran Associates Inc. All rights reserved.