The National Security Agency (NSA), Cybersecurity and Infrastructure Security Agency (CISA), FBI, Department of Energy (DOE), and Environmental Protection Agency (EPA) have released a cybersecurity advisory warning of an active cyber threat to Siemens S7 Series programmable logic controllers (PLCs). 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. Actors leverage Internet scanning services to find Internet-exposed PLCs running outdated software or that are otherwise poorly protected. The advisory covers S7-200, S7-300, S7-400, S7-1200, and S7-1500 series models across critical manufacturing, energy, water and wastewater, chemical, food and agriculture, and commercial facilities sectors. Exploitation could lead to disruption of critical industrial processes, safety incidents, equipment damage, and data compromise.