Last Updated: August 19, 2026

Overview

The National Security Agency (NSA) has issued a cybersecurity advisory to inform owners and operators of Siemens S7-series Programmable Logic Controllers (PLCs) of an active cyber threat to these industrial control systems (ICSs).

Recommended Actions

EPA recommends water and wastewater systems review the tactics, techniques, and procedures (TTPs) in the advisory and the potential operational impacts to learn more about this threat, and apply the recommended mitigation actions and preventative hardening actions to minimize the likelihood of an attack.

For the full CISA report visit Defending Against an Active Threat to Siemans S7 Series PLCs

Remember- If you see something, say something:

Report suspicious activity and threats of violence, including online threats as appropriate to local law enforcement, FBI – Richmond Field Office, and the VSP Fusion Center. The VSP Fusion Center will take appropriate action and investigate reports of concern with appropriate state and federal partners. The EPA Incident Action Checklist for Cybersecurity also includes resources for preparation and recovery. 

Maintain vigilance to protect critical infrastructure.  Please ensure your workforce is aware of the potential threats and that they know to report any and all suspicious activity to the VSP Fusion Center.  Thank you for taking immediate action to harden assets and protect people and critical infrastructure.

Cybersecurity & Infrastructure Security Agency (CISA)
Incident Reporting Webpage
Email: report@cisa.gov
Phone: 1-844-Say-CISA (1-844-729-2472)
Virginia Fusion Center
Virginia Fusion Center: Incident Reporting Webpage
Phone: 877-4VA-TIPS (877-482-8477)

View the VDH-Office of Drinking Water Website for Waterworks Cybersecurity for more resources.