Step 3: Cut The Noise
How to cut alert fatigue and build detections that actually matter
In many organisations, the security operations centre (SOC) is overwhelmed. The volume of alerts coming from tools like Sentinel, Defender for Endpoint, and Cloud Apps is high, and growing. Spending more time triaging noise than they are stopping real threats, does this sound familiar?
This isn’t about analyst headcount or tool choice. It’s about architecture. If alerts lack context, if rules aren’t aligned to threat models, and if telemetry isn’t prioritised for security value, then teams fall into the trap of reactive operations. Detections are missed, alerts are ignored, and fatigue sets in.
From Logs to Learning: A Better Detection Strategy
The goal should be to build detection that learns, not logs that shout. To do this:
- Use adversary simulation to inform detection logic based on attacker behaviours, not just CVEs.
- Enrich alerts using KQL to bring in user, identity, device, and behavioural context.
- Consolidate and deduplicate alerts using automated playbooks.
- Shift your engineering focus to building correlation logic, not just ingesting more data.
Identity-based attacks are quiet, fast, and common.
According to Microsoft’s 2024 Cyber Signals Report, over 80% of breaches involve compromised credentials. Not malware. Not exotic exploits. Just attackers logging in as legitimate users, often using techniques that bypass endpoint protection entirely.
This shift means traditional indicators, antivirus hits, signature detections, suspicious processes, are no longer reliable early warning signs. Instead, the signals of compromise hide in identity logs, user behaviour, data access patterns, and cloud resource manipulation. Unfortunately, these are the very signals most teams aren’t equipped to monitor effectively.
Why Alert Volume ≠ Protection
In one Microsoft 365 E5 client we recently supported, Sentinel was generating nearly 10,000 alerts per week. Less than 2% were ever reviewed. Most were low or medium severity, generated by default rules, and rarely linked to specific threat behaviours.
Defender for Endpoint was active across a high proportion of devices in the estate and, due to the scale, alerts were treated in isolation. They were missing a trick; Defender for Cloud Apps (MCAS) produced policy violations , but no one was tracking whether they correlated with risky login patterns. Entra ID identity protection was running but not enforcing risk-based Conditional Access.
From a tooling perspective, everything looked fine. But when we tested detection through purple teaming, we walked through three stages of an attack path, initial credential theft, privilege escalation, and sensitive data access, without triggering a single high-confidence alert. It wasn’t a tooling failure. It was a tuning failure.
Shift from activity monitoring to threat detection
The problem wasn’t the quantity of alerts, or even the rules themselves. It was the lack of behavioural linkage.
Modern attacks don’t trigger one big alarm. They trigger a series of weak signals, failed logins, unusual admin role assignment, cloud configuration change, endpoint process injection, that only make sense when viewed together. The key is joining these dots.
This means going beyond default analytics and building detection logic that understands attacker behaviour. It means linking Defender for Endpoint to Sentinel, so endpoint telemetry feeds broader correlation rules. It means using Entra ID sign-in logs to enrich every alert with identity context. It means tracking session tokens, OAuth grants, and risky sign-ins in real time, not after the fact.
Most importantly, it means treating security alerts not as isolated notifications, but as pieces of a wider attack story that you need to reconstruct quickly.
A Real-World Example
A purple team simulation for a financial services organisation emulates a common credential-based attack.
Using legitimate credentials for a contractor account, log in is from a new IP range and accessed is gained to SharePoint sites that contained sensitive commercial data. A browser session is used to authenticate, mimicked normal working hours, and content is exfiltrated over HTTPS.
Defender for Cloud Apps flags a location anomaly. Entra ID tags the sign-in as medium risk. But neither alert is escalated or triaged. Sentinel hasn’t fired a correlation rule, because those signals aren’t connected.
After a new detection framework, those same behaviours trigger a three-stage response:
- Entra ID tags the login.
- Cloud Apps flags data movement.
- Sentinel correlates the pattern using custom KQL analytics.
That combination produces a high-severity, confidence-weighted alert, sent directly to the response team. The tools didn’t change.
The Payoff: Confidence Without Complexity
This isn’t about building a perfect detection engine. It’s about reducing noise and improving signal fidelity.
By moving from isolated monitoring to behavioural correlation, the IT team reduced their alert volume by 70%, while improving detection coverage across common attack paths. Analysts had fewer, but more meaningful, alerts to review. And when a genuine compromise occurred two months later, this time via a contractor email compromise, they contained it in under 30 minutes.
Not because a tool shouted. But because the system was finally listening for the right things. Is your alert volume a strength, or your biggest blind spot?
Industry Context
SANS 2023 SOC survey found 68% of analysts cited alert fatigue as their #1 reason for burnout. JUMPSEC’s work aligns directly with this challenge: instead of adding more tech, we improve the logic and trust in what’s already deployed.
Effective detection isn’t about volume. It’s about trust in signal quality. SOCs don’t need more tools, they need more signal, more context, less noise, and constant adaptation.