Strengthening national cyber resilience through observability and threat hunting

Summary

The NCSC highlights large variation in organisations’ abilities to monitor their environments (observability) and to proactively hunt for threats. It argues these two capabilities are interdependent: without broad visibility you cannot effectively hunt for intrusions. The blog sets out practical steps to improve observability, move beyond fragile Indicators of Compromise (IOCs) to Tactics, Techniques and Procedures (TTPs), and recommends where organisations can get support from NCSC-assured providers.

Key Points

Observability = clear, detailed visibility across networks, systems and services; it is the foundation for detection and hunting.
Threat hunting is proactive searching for signs of intrusion using hypotheses informed by attacker behaviour and threat intelligence.
Gaps in visibility create “dark corners” (users, devices, cloud, shadow IT) that inhibit detection and investigation.
Organisations should maximise visibility and the ability to query combined datasets across on-premises and cloud systems.
Relying solely on IOCs is fragile; attackers can evade them quickly using techniques like Fast Flux, cloud infrastructure or living-off-the-land tools.
Adopt TTP-based detection (how attackers operate) to gain more resilient, longer-lived detection capability.
Effective TTP use requires comprehensive visibility, searchable/correlatable infrastructure and skilled defenders who can form and test hypotheses.
NCSC can provide assurance and support via Enhanced-level Cyber Incident Response providers and the Cyber Adversary Simulation (CyAS) service.

Content summary

The blog defines observability and threat hunting, then explains why the two are inseparable: you can’t hunt what you can’t see. It outlines common visibility shortfalls (partial monitoring, lack of identity/cloud telemetry, siloed data) and recommends maximising visibility and queryability across combined data sets, with vendor engagement and standards (RFC9424) to improve monitoring.

It warns against over‑reliance on IOCs, describing their short lifespan and ease of evasion, and promotes TTPs as a more robust basis for detection and hunting. The post lists example technical patterns mapped to plain English to show how TTPs look in practice. Finally, it points organisations without internal capability to NCSC-assured services and the upcoming CyAS for validation of hunting capabilities.

Context and relevance

This guidance is important for security teams, cloud and platform owners, and organisations using external providers. As enterprise estates grow in complexity (cloud, SaaS, IoT, shadow IT), blind spots increase; the blog links this problem to national cyber resilience. The shift from IOC-centric to TTP-driven detection reflects broader industry trends towards behaviour-based, hypothesis-led hunting and emphasises the need for tooling and skills that can search and correlate diverse telemetry.

Why should I read this?

Because if your security team can’t see large parts of your estate, they’re flying blind. This piece tells you what to fix first (visibility and queryable data), why chasing IOCs won’t cut it long-term, and where to get help if you’re short on skills. Quick, practical and directly relevant if you care about actually spotting attackers rather than just reacting to noisy alerts.