Security Symmetry in Embedded Systems: Using Microsoft Defender for IoT to Detect Firmware Downgrade Attacks

Nowadays, the world witnesses cyber attacks daily, and these threats are becoming exponentially sophisticated due to advances in Artificial Intelligence (AI). This progress allows adversaries to accelerate malware development and streamline the exploitation process. The motives vary, and so do the consequences. Unlike Information Technology (IT) breaches, Operational Technology (OT)—such as manufacturing plants, electric grids, or water and wastewater facilities—compromises can have life-threatening or environmentally hazardous consequences. For that reason, this article explores a potential cyber attack against an OT environment—firmware downgrade—and proposes a solution for detection and response by implementing Microsoft Defender for IoT (D4IoT), one of the leading products on the market for OT monitoring. To detect the malicious firmware downgrade activity, D4IoT was implemented in a pre-commissioning (non-production) environment. The solution passively monitored the network, identified the deviation, and generated alerts for response actions. Testing showed that D4IoT effectively detected the firmware downgrade attempts based on a protocol analysis and asset behavior profiling. These findings demonstrate that D4IoT provides valuable detection capabilities against an intentional firmware downgrade designed to exploit known vulnerabilities in the older, less secure version, thereby strengthening the cybersecurity posture of OT environments. The explored attack scenario leverages the symmetry between genuine and malicious firmware flows, where the downgrade mimics the upgrade process, aiming to create challenges in detection. The proposed solution discerns adversarial actions from legitimate firmware changes by breaking this functional symmetry through behavioral profiling.