Key Takeaways:
- OT incidents often start with ordinary enterprise weaknesses, such as shared credentials and permissive remote access, rather than sophisticated attacks on process networks.
- Management and remote-access planes are the primary OT attack surface, and locking them down is crucial to preventing incidents.
- Detection and recovery capabilities are critical to containing and recovering from OT incidents, but are often inadequate in many environments.
- Identity and tiering weaknesses can significantly amplify incident impact, and addressing these issues is essential to limiting the blast radius.
- CISOs should prioritize containment and recovery in their OT security strategies, rather than just focusing on hardening and prevention.
Introduction to OT Security
OT incidents rarely start with "OT attacks." They start with ordinary enterprise weaknesses: shared credentials, remote access shortcuts, management systems that bridge zones too easily, and monitoring that stops short of operations. When those weaknesses line up, an initial IT compromise becomes an OT event, and the deciding factor is no longer whether the activity is detected, but whether the environment can be contained and recovered without extended outage. What matters is that these failure patterns repeat across industries, which means they can be anticipated and solved – but only if recovery is treated as a security control, not an afterthought.
Recurring OT Security Patterns Across Industries
Sygnia, a premier cyber technology and services company, has extensive experience helping organisations’ IT/OT environments respond to cyber incidents and strengthen enterprise-wide cyber security. Across numerous OT security assessments, adversary simulations, and incident response engagements conducted globally between 2022 and 2025, one thing became clear: OT risk does not distribute evenly across the environment. It concentrates. A small number of control points, such as remote access, management infrastructure, identity boundaries, monitoring coverage, and recovery systems, repeatedly determined whether incidents stayed contained or escalated into operational disruption. Attackers did not need deep process knowledge to cause impact either, as access paths built for administration and support provided a reliable entry.
Core OT Defences and IT-OT Traffic
Roughly one-third of assessed environments showed solid progress in core OT defences, including disciplined remote-management designs and a hardened Production DMZ. This maturity was frequently offset by overly permissive traffic flows between IT and OT. In multiple environments with otherwise sound segmentation, these allowances became the primary escalation path once initial access was established, limiting the practical value of the PDMZ during incidents. OT backup implementations were generally comprehensive, covering data, configurations, snapshots, and machine state. However, in practice, recoverability remained weak. In approximately 50% of assessments, OT backup platforms were reachable from IT or management tiers or lacked offline or immutable copies.
Management and Remote Access as Primary OT Ingress
In roughly 60% of adversary simulations, access to OT was achieved through management infrastructure, most commonly jump servers. These systems were rarely compromised through exploitation; misconfiguration, excessive trust, and inherited privileges allowed attackers to move into OT via legitimate access paths, consistent with living-off-the-land techniques observed in real incidents. Detection worked where deployed, but blind spots persisted elsewhere. More than 50% of assessed environments had limited or no SIEM or SOC telemetry in OT or management zones. By contrast, around 30% demonstrated mature detection capabilities, successfully identifying simulated attacker activity, particularly within operations centres.
Identity and Tiering Weaknesses
In approximately 60% of engagements, identity-related issues were present, including credential reuse across IT and OT, non-rotated credentials, oversized administrative groups, or missing MFA. These conditions significantly increased the likelihood that an IT-originating compromise would escalate into an OT outage, extending dwell time, raising recovery costs, and increasing regulatory exposure. Third-party access remained a consistent risk, with vendor laptops or site-to-site tunnels providing the easiest path into OT environments in roughly 40% of cases. Third-party access was often weakly monitored or insufficiently controlled, creating trusted pathways that bypassed internal safeguards and reduced visibility during incidents.
Cross-Industry Trends and Operational Impact
Management and remote-access planes are the primary OT ingress, and attackers enter through administrative paths already trusted by the environment. The implication is that OT risk concentrates upstream of the process network. Once management planes are compromised, segmentation offers limited protection. For incident response teams, this means containment often depends on how quickly management access can be restricted, rather than on controls deeper in the process network. Detection works where deployed, but blind spots persist elsewhere. Environments that combined event logging, endpoint protection, and SIEM-integrated network detection across both IT and OT showed materially stronger detection outcomes.
Recovery and Containment
Recovery must be tamper-resistant, not just present. Backups were common across environments, but recoverability was not. Online-only backup systems and untested disaster recovery plans remained vulnerable to the same access paths used during an attack. Without immutable or offline copies and rehearsed restoration procedures, recovery timelines extended significantly during destructive events. In OT incident response, recovery capability determines whether an organisation returns to operation on its own terms or remains constrained by the attacker’s impact. Identity and tiering hygiene shapes blast radius, and identity failures consistently amplified incident impact.
What CISOs Should Do Next
CISOs should lock down management and remote access, treating management and remote-access planes as the primary OT attack surface. They should standardise jump servers and OT-dedicated remote access, enforce MFA everywhere, and remove shared or persistent access. Vendor sessions should be per-person, time-bound, and recorded. CISOs should also extend visibility across escalation paths, making detection follow how attackers move, not how networks are drawn. They should forward logs from VPNs, firewalls, jump hosts, identity systems, and backup platforms to the SOC, and add host and identity telemetry where OT visibility drops off.
Conclusion
OT incidents rarely begin with sophisticated attacks on process networks. They start with ordinary enterprise weaknesses: shared credentials, permissive remote access, trusted management paths, and blind spots between IT and OT. What determines the outcome isn’t whether attackers get in — it’s whether organisations can contain and recover when they do. From years of OT assessments and incident response engagements, a consistent pattern emerges. The environments that limit operational impact are not those with the most tools, but those that make deliberate architectural choices, including tightly governed management access, enforced identity boundaries, detection that follows attacker movement across zones, and recovery that works even after IT and management layers are compromised.
