U.S. security agencies have warned that Siemens programmable logic controllers present a gateway for cyberattacks on critical infrastructure, with hackers deploying artificial intelligence to breach the systems. The joint advisory from the NSA, CISA and FBI targets five versions of the Simatic S7 series, particularly the S7-1200 PLC, which regulates operations at U.S. water treatment plants, energy facilities, chemical plants and agricultural systems.
Successful intrusions could disrupt critical processes, trigger safety incidents or damage equipment. The alert follows thirty cyberattacks on a Minnesota water supply system over two days in late July. CISA had previously warned of rising attacks on programmable controllers on July 30, and Siemens issued its own security advisory to customers in early July.
Experts suspect a link to Iran behind the recent wave of attacks on water systems across multiple states. President Donald Trump disputed that assessment.