Smart Grids (SGs) based on IoT are of importance. SGs can improve the profitability and reliability of the electrical system by incorporating renewable energy and highly developed communication technologies. Furthermore, the communications network plays a fundamental role in electrical networks, and trends favor the implementation of SG with IoT devices. However, these IoT-based SGs are vulnerable to cyber-attacks. This article analyzes the behavior of malware using System Dynamics and calibration with stochastic optimization. Finally, some conclusions are given, which identify research work to be carried out to support the development of effective risk management schemes.