Topic starter
25/10/2026 11:10 am
TL;DR: A 45-minute delay between alerting and blocking leaves OT ransomware room to keep moving, according to TXOne Networks. OT security needs enforcement speed, not just monitoring, or production disruption can still follow an early alert.
Editorial analysis by NHI Mgmt Group, based on content published by TXOne Networks: “The Visibility Gap is a Myth”.
By the numbers:
- 100% of ransomware incidents they monitored last year still caused operational shutdowns.
- 75% resulted in a partial operational shutdown.
- 25% resulted in a full operational shutdown.
Key questions
Q: Why does OT ransomware still cause shutdowns when detection works?
A: Detection works because it identifies the attack, but that does not mean it can prevent the attack from progressing.
Q: How can security teams tell whether an OT assessment is actually working?
A: An assessment is working when it produces approved, executable remediation plans rather than static reports.
Q: What breaks when OT teams rely on visibility tools without inline prevention?
A: Visibility-only architectures break at the point where detection must become action.
Practitioner guidance
- Define a prevention-time objective Set a maximum tolerable delay between threat detection and blocking in OT environments, then test whether current controls can meet it under real operational constraints.
- Map the full alert-to-enforcement chain Document every handoff from alert generation to firewall, NAC, or endpoint action, including the approvals that slow containment.
- Separate visibility from enforcement in control reviews Score discovery, assessment, and blocking as distinct capabilities so visibility tools are not mistaken for prevention controls.
Bottom line: OT security fails when monitoring is mistaken for a control that can stop active ransomware before production impact.
Glossary terms: Passive Monitoring, Prevention Gap, Inline Enforcement, Operational continuity control
Explore further
View Full Forum → | NHI Foundation Course → | Our Services → | Read the full analysis →
This topic was modified 7 days ago by NHI Mgmt Group
27/10/2026 7:17 pm
Visibility gap is the wrong label for this problem: the issue is a prevention gap created by out-of-band monitoring and slow enforcement. Discovery tools still matter, but they do not change the fact that malicious action continues while teams coordinate a response. Practitioners should evaluate OT controls by how quickly they can block, not by how much they can see.
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.
A question worth separating out:
Q: What is the difference between OT visibility and OT prevention?
A: OT visibility tells you what is happening, while OT prevention changes whether the activity can continue. Visibility is typically passive and out of band, so it supports detection and investigation. Prevention is inline or otherwise able to block malicious traffic in real time, which is the capability needed to stop operational impact.
👉 Read our full editorial: Prevention gaps outlast visibility in OT ransomware defence
This post was modified 7 days ago by NHI Mgmt Group