IoT systems, along with internet-accessible operational technology (OT) deployments that bypass legacy isolation, represent an ongoing information security challenge. Key factors include the variety of non-standard endpoints, legacy approaches to remote access for maintenance, adjacency to vulnerable IT networks, and an ever-increasing attack surface as technology modernizes. While vendor solutions continue to grow, so does the threat landscape, exemplified by malware targeted at industrial control systems and the formation of large IoT botnets. Because these systems are vital to critical infrastructure, they are often a target for nation-state actors.
In recent years, the US Cybersecurity and Infrastructure Security Agency (CISA) and former government officials have issued warnings regarding advanced persistent threat actors such as Volt Typhoon, allegedly backed by the Chinese state, that have infiltrated and maintained access to critical infrastructure, including energy and water utility systems. Ransomware attacks that move laterally from IT to OT networks, or that use the former to disrupt the latter, remain an issue, following the model of the 2021 Colonial Pipeline attack and continuing with breaches such as the one affecting major US steel producer Nucor Corp. in 2025. Canadian utility Nova Scotia Power also reported a ransomware attack that disrupted the ability to read billing information from customer smart electrical meters.
When survey respondents are asked to identify threats to IoT systems, the discussion quickly extends past IoT endpoints themselves. In a 2023 study conducted by S&P Global Market Intelligence 451 Research, the top cited IoT security threat was unpatched application security vulnerabilities, reflecting the difficulty of patching IoT and OT devices after they have been deployed. That dropped to second in 2024, superseded by attacks against a centralized control point, reflecting potential shifts in the behavior of threat actors. In our latest study, vulnerable IoT databases or data stores (32%) have risen to become the top concern. Unpatched application security vulnerabilities (28%) remain second, followed by attacks against unsecured networks between device endpoints and central control points (27%).
https://blog.451alliance.com/transition-from-isolation-to-exposure-brings-evolving-threats-to-iot-and-ot-systems/