Poland Power Grid Cyberattack: OT Security Lessons for Critical Infrastructure

Overview

In December 2025, a coordinated cyberattack targeted Poland’s power grid, impacting approximately 30 distributed energy resource (DER) sites including wind, solar, and combined heat and power facilities.

The attack focused on operational technology (OT) environments, specifically communication devices and remote-control infrastructure, disrupting visibility and control.

While no widespread power outage occurred, the incident demonstrates a serious and credible threat to OT environments, particularly at the grid edge, where security controls are often weaker.

What Happened in the Poland Power Grid Cyberattack?

• Attackers targeted OT communication devices such as RTUs and gateway systems.
• Around 30 DER facilities lost remote monitoring and control capabilities.
• Some OT devices were rendered inoperable (bricked), requiring manual replacement.
• The attack did not cause power outages, mainly due to grid redundancy and manual failover.
• Security researchers have linked the activity to Russia-aligned threat actors, consistent with previous attacks on energy-sector OT systems.

Why This Matters

• Distributed Energy Resources (DERs) are increasingly targeted because they are:
  • Geographically dispersed
  • Often remotely managed
  • Less mature in cybersecurity controls compared to core SCADA
• Disruption of communications alone can significantly degrade operational awareness and response.
• The incident reinforces that OT attacks may aim for disruption and damage, not just espionage.

Observed Attack Characteristics

• Targeting of OT network edge devices
• Disruption of telemetry and control channels
• Likely use of destructive malware or unauthorized configuration changes
• Focus on availability and operational impact, not data theft

ProArch Recommendations on How Energy Operators Can Reduce OT Cyber Risk

A. Strengthen Network Segmentation

• Enforce strict separation between IT and OT networks using firewalls and dedicated OT DMZs.
• Isolate DER sites and communication gateways from corporate IT access.
• Limit remote access to OT systems using:
  • VPNs
  • Jump servers
  • Least-privilege access controls

Objective: Prevent lateral movement and reduce exposure of OT systems.

B. Harden OT EDR / Endpoint (OT-Aware)

• Ensure OT-compatible endpoint protection is deployed where supported.
• Disable unnecessary services and remote access on OT devices.
• Monitor for:
  • Unauthorized configuration changes
  • Unexpected firmware or software updates
• Apply vendor-approved patches during maintenance windows.

Objective: Reduce attack surface on OT endpoints and gateways.

C. Backup & Restore

• Maintain offline (air-gapped) backups of:
  • RTU/PLC configurations
  • Firmware images
  • OT system settings
• Regularly test restore procedures to ensure operational recovery.
• Document manual fallback procedures for loss of communications.

Objective: Enable rapid recovery from destructive or disruptive OT attacks.

What SOC and OT Teams Should Be Watching For

• Alerts for sudden loss of OT communications
• Detection of unauthorized remote access attempts
• Correlation of multiple DER site disruptions
• Playbooks focused on availability and recovery, not just containment

Conclusion

This Poland power grid cyberattack highlights a growing trend of targeted attacks against energy-sector OT environments, especially distributed and remote assets. Even without causing outages, disruption of OT communications can have serious operational and safety implications.

Organizations operating OT or energy infrastructure should:

• Strengthen OT network segmentation
• Improve detection of communication disruptions
• Ensure resilient backup and recovery processes
• Update SOC and OT playbooks to address destructive and availability-focused attacks