Topic starter
23/10/2026 12:46 am
TL;DR: Prolonged OT compromise can stay hidden for months, Dragos reports, with one utility compromised for over 300 days before outside investigators alerted it and a Minnesota water-sector wave affecting more than 30 utilities. Passive monitoring gives operators the traffic context needed to spot unauthorized activity before physical operations are exposed.
Editorial analysis by NHI Mgmt Group, based on content published by Dragos: “Why xOT Monitoring Matters: Lessons from an OT Threat Hunter”.
By the numbers:
- The adversary had been present in their environment for over 300 days before anyone knew.
- Over a single weekend, more than 30 municipal water utilities had their OT systems compromised.
Key questions
Q: Why does hidden OT access create so much operational risk?
A: Hidden access matters because industrial operations depend on knowing which systems are talking, what commands are being issued, and whether the control environment has been altered.
Q: What are the signs that OT monitoring is failing to provide real visibility?
A: Common signs include unexplained blind spots in protocol coverage, inability to interpret device-to-device traffic, no reliable baseline for normal operations, and response decisions that depend on guesswork after an incident.
Q: What breaks when OT environments are monitored only with IT security tools?
A: IT tools often miss industrial protocol context, cannot safely instrument many legacy assets, and can introduce availability risk if deployed inline.
Practitioner guidance
- Implement passive OT network monitoring Deploy passive sensors that observe industrial traffic without touching assets, especially where endpoint agents or active scanning would threaten uptime.
- Baseline normal process communication Build per-site baselines for device peers, command sequences, and engineering access windows so deviations are obvious during threat hunting.
- Map exposed OT assets and remote pathways Inventory externally reachable PLCs, HMIs, and remote access routes, then prioritize the paths that could let an attacker reach operational control systems.
Bottom line: The central problem is not a lack of security products, but a lack of operational visibility into the systems that influence physical outcomes.
Glossary terms: Extended Operational Technology, Passive Monitoring, Operational Baseline, Visibility Debt
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This topic was modified 6 days ago by NHI Mgmt Group
23/10/2026 9:48 am
Extended OT visibility is now a governance requirement, not a technical enhancement. In xOT environments the question is no longer whether a SOC can ingest more telemetry, but whether operators can prove they see the systems that influence physical operations. That shifts monitoring from an optional detector to a foundational control for resilience, safety, and decision-making. Practitioners should treat visibility as part of the control architecture, not a bolt-on sensor layer.
A few things that frame the scale:
- Only 5.7% of organisations have full visibility into their service accounts, according to the Ultimate Guide to NHIs.
- 96% of security operations teams report critical blind spots, most commonly in cloud infrastructure (74%) and identity and access behaviour (67%).
A question worth separating out:
Q: How should security teams decide between passive OT monitoring and inline controls?
A: In OT, passive monitoring is usually the safer choice because it reduces the chance of disrupting production while still giving defenders useful traffic context. Inline controls may be appropriate in limited cases, but only when the operational risk is understood and the control can fail safely without affecting physical processes.
👉 Read our full editorial: xot visibility is now the control plane for operational resilience
This post was modified 6 days ago by NHI Mgmt Group