SilentShield 2026 Exercises: CISA Red Team Penetrates Two Critical Infrastructures, One Without Any Detection

The CISA releases the results of its SILENTSHIELD exercises: two U.S. critical infrastructure organizations tested, two successful compromises. One issued no alerts. Meanwhile, over 100 U.S. water systems were attacked in July 2026.

SILENTSHIELD: CISA's Red Team Targets Critical Infrastructure

The Cybersecurity and Infrastructure Security Agency (CISA) has just released the results of its SILENTSHIELD exercises—simulated attacks conducted on the live networks of U.S. critical infrastructure organizations without their knowledge, to replicate real-world conditions.

Outcome: two organizations tested, two complete compromises by the red team. One of them detected no alerts and remained unaware throughout the entire exercise.

How CISA Conducted the Exercises

Spear phishing as the initial vector. Access was gained via targeted phishing against employees identified through OSINT. No zero-day vulnerability exploitation was required to gain entry.

Living-off-the-land (LotL) for lateral movement. Once inside, the red teamers used only legitimate tools already present on the systems (PowerShell, WMI, admin tools). Result: no malicious signatures to detect.

Persistence for weeks. Maintaining stealthy access over time closely mirrors APT tradecraft—real attackers don’t rush.

Why One Organization Saw Nothing

The blindfolded organization exhibited the classic defensive gaps of non-security-specialized operators: insufficient logging, detection based solely on signatures, and a lack of proactive threat hunting.

This profile is the norm, not the exception, in critical infrastructure—utilities, water, energy—where IT teams are understaffed and OT systems are outdated.

The Context: 100+ Water Systems Attacked in July

The Register simultaneously reports that over 100 U.S. water systems were hit by cyberattacks in July 2026. The gaps documented by SILENTSHIELD align exactly with the vectors exploited in these real-world incidents.

What Operators Must Do

Priority 1: Centralized logging. Without complete logs of connections, PowerShell executions, and admin access, behavioral detection is impossible.

Priority 2: Monitor LotL activity. PowerShell, WMI, and legitimate admin tools can be monitored for anomalous patterns—even without malicious signatures.

Priority 3: CISA assessments. CISA offers free assessment services to critical infrastructure operators. This is a resource to use before a real attacker serves as an unplanned red team.

Action now: Audit your logging. If you lack centralized logs of connections and admin executions, that’s Priority 1 before any other security investment. Contact CISA for a free assessment: cisa.gov/resources-tools/services/cisa-assessments