Why OT Organisations Can’t Afford to Ignore Endpoint Security Anymore

Ransomware may start in IT, but it doesn’t always stop there. In recent years, critical infrastructure organisations have become increasingly familiar with cyberattacks. From energy and water utilities to manufacturing and transportation systems, operational technology (OT) environments are no longer spared—they’re being targeted not only for disruption or espionage, but also for financial gain through ransomware and data theft.

A recent ransomware incident involving a major North American electric utility underscores how serious the threat has become. While power generation and distribution were reportedly unaffected, attackers breached IT systems, accessed sensitive customer data, and deployed ransomware. Though the OT environment was not directly compromised this time, the attack highlights just how close cybercriminals can get—and how much worse the outcome could have been.

Yet despite growing awareness, cybersecurity efforts still tend to focus on perimeter defence and IT network hardening. One of the most overlooked—and most frequently exploited—vulnerabilities lies at the very edge: OT endpoints.

The Hidden Risk at the Edge of Your Operations

Unlike IT systems, OT devices such as PLCs, HMIs, and remote terminal units were never designed with security in mind. Many of these endpoints still rely on default or static passwords for local and remote access, making them low-hanging fruit for attackers who are increasingly probing OT environments for soft entry points.

Once a static credential is compromised—whether through phishing, credential stuffing, or insider misuse—attackers can gain persistent access to critical systems. In a worst-case scenario, this could allow them to:

• Disrupt industrial processes
  
• Alter control logic or setpoints
  
• Move laterally across converged IT/OT networks
  
• Launch ransomware operations from inside the OT environment

This is not theoretical. Multiple incident reports, including nation-state operations, have shown that attackers are actively seeking—and exploiting—poorly secured OT endpoints as initial footholds.

Regulations Are No Longer Optional

The urgency is reflected in evolving regulatory frameworks. The NIS2 Directive, enforced across the EU, and international standards like IEC 62443 both mandate stronger access controls and identity verification mechanisms, especially for critical systems.

Of particular relevance is IEC 62443 Foundational Requirement 1 (FR1): Identification and Authentication Control, which requires organisations to establish and enforce secure identity mechanisms for both users and devices accessing OT systems.

Under these regulations, OT organisations are expected to:

• Uniquely identify all users
• Apply role-based access limitations
• Implement strong or multi-factor authentication
• Manage credentials regularly and maintain audit trails

Compliance is no longer a matter of best practice—it’s becoming a legal requirement.

Moving Towards Stronger Authentication

Improving endpoint security begins with phasing out legacy password-based access. This means rethinking how operators, engineers, and third-party vendors authenticate to OT systems—especially when working in distributed, remote, or air-gapped environments.

Some organisations are adopting dynamic authentication mechanisms that eliminate the need for shared or static credentials entirely. These approaches not only reduce the attack surface but also limit lateral movement, even if one endpoint is compromised.

One example includes swIDch’s OT authentication solution, which generates one-time access codes that function without network connectivity—enhancing security without adding operational complexity.

Don’t Let Endpoints Be the Weak Link

Cybersecurity strategies often focus on firewalls, segmentation, and perimeter defences. But in a world of growing ransomware threats and tightening regulations, endpoint security must be treated as a frontline defence—not an afterthought.

By proactively replacing static authentication methods and aligning with standards like IEC 62443 FR1, OT organisations can not only harden their environments against attack but also build the resilience expected of critical infrastructure operators in today’s threat landscape.