Malicious software spread modeling and control in cyber-physical systems

Cyber-physical systems are interactive intelligent systems integrating computing units and physical objects through information networks. They have been widely used in critical infrastructures, and are increasingly vulnerable to malicious software attacks. To explore the spread mechanism of malicious software in cyber-physical systems from a macroscopic perspective, this work proposes a new malicious software spread model with time delay, and analyzes its complex dynamic behavior by using the stability theory and bifurcation theorem. A hybrid bifurcation control method is presented to control adverse bifurcations that cause harmful behavior of cyber-physical systems, and the influence of control parameters on the Hopf bifurcation threshold is revealed. Cyber-physical systems with the proposed method can be stabilized, which behave as expected during malicious software spread. The simulations show that the proposed control method can advance or postpone the threshold of Hopf bifurcation, thus making cyber-physical systems achieve a stable state. Consequently, damage and disruption to cyber-physical systems caused by malicious software are effectively reduced. (C) 2022 Elsevier B.V. All rights reserved.