Summary
However, ongoing PLC targeting activity is broader than Siemens PLCs. All PLC owners and operators should apply relevant mitigations to reduce the risk to their devices and systems. The Siemens-specific content in this advisory should be understood and applied as one subset of the wider threat landscape. Inventory all Siemens S7 Series programmable logic controllers (PLCs) Harden PLC services, protocols, and ladder logic integrity Hunt for anomalies that may indicate a compromise The National Security Agency (NSA), Cybersecurity and Infrastructure Security Agency (CISA), Federal Bureau of Investigation (FBI), Department of Energy (DOE), and Environmental Protection Agency (EPA)—hereafter referred to as the authoring agencies—are releasing this Cybersecurity Advisory to warn owners and operators of industrial control systems (ICSs) of an active cyber threat to Siemens S7 Series PLCs and provide relevant mitigations to protect and defend them. The threat actors are conducting reconnaissance and capability development against U.S.-based Siemens PLC installations using AI-generated exploitation scripts disguised as legitimate monitoring tools. The actors leverage Internet scanning services to find Internet-exposed PLCs running outdated software or that are otherwise poorly protected.