December 26, 2025 5 Minute Read

• Unified Security Fabric: Eliminates the silos between SIEM (Sentinel) and XDR (Defender) to provide a single, correlated view of attacks across identity, cloud, and network layers.
• Operational Efficiency: Streamlines SOC workflows by replacing fragmented portals with a single incident queue, reducing analyst fatigue and accelerating time-to-response.
• Strategic ROI: Maximizes the value of existing data ingestion and security investments through AI-powered insights and coordinated, cross-system automation.

For years, security vendors have treated SIEM and XDR as two distinct pillars of their security stack - one built for broad log visibility and compliance, the other designed for high-fidelity detection and rapid response. However, as hybrid environments expanded and attackers began exploiting identity, endpoint, cloud, and network surfaces simultaneously, those boundaries blurred.

SOC analysts don’t experience incidents as “SIEM problems” or “XDR problems.” They experience security problems — lateral movement, credential theft, privilege escalation, and multi-stage attacks that cut across every layer of the enterprise. The old model of separate portals, separate incident queues, and separate correlation engines is simply too inefficient to handle modern attacks.

This is why Microsoft’s migration of Sentinel into the Unified Defender XDR SecOps portal is so significant. It is not a UI refresh, nor is it about forcing products together. It is an outcomes-driven re-architecture of the detection and response experience.

By merging analytics, telemetry, automation, and AI assistance into a single operational fabric, Microsoft is shifting the focus from separate tools to outcomes: faster detection, deeper correlation, smoother investigations, and more decisive response.

Let’s analyze the impact of this shift through three strategic lenses: Security, Operational Efficiency, and Commercial Value.

1. The Security Lens: Stronger Detection, Correlation & Resilience

Unified Detection Across SIEM + XDR

In the unified model, Sentinel and Defender XDR no longer act as separate systems producing separate incidents. Instead, they operate as a single detection fabric, correlating:

• Endpoint behaviour
• Identity anomalies
• Email threats
• Cloud events
• Network logs
• OT and IoT telemetry
• Third-party logs from firewalls, proxies, CASBs, and more

This expands the detection surface far beyond the boundaries of traditional XDR tools, which typically rely heavily on their own native telemetry.

Security outcome:

Correlation at the Incident Level, Not the Alert Level

The unified SecOps portal emphasizes incident-level correlation, rather than stitching together unrelated alerts across products.

This greatly improves the defender’s ability to understand the true scope of an attack, whether it’s a compromised user identity linked to a poisoned OAuth app, or lateral movement from endpoint to server. This level of cross-domain correlation was technically possible before - but operationally fragmented. Now it’s native.

Security outcome:

A More Complete Investigation Fabric

The unified investigation graph creates a holistic “storyline” of an attack. It merges Sentinel’s long-term log retention and third-party telemetry with XDR’s behavioural analytics. This supports scenarios like:

• Investigating an attack that starts with a phishing email (MDO), moves to an endpoint (MDE), then leverages legacy protocols (Sentinel logs).
• Hunting for zero-day exploitation activity using cloud logs and endpoint signals simultaneously.
• Correlating OT anomalies (via Sentinel connectors) with IT behaviour (via Defender XDR).

Security outcome:

AI-Powered Security With Real Context

Copilot for Security brings generative AI into the defender workflow, but its value multiplies when grounded in both SIEM and XDR data. With unified context, Copilot can:

• Summarise entire incidents in seconds
• Identify lateral movement that a human might miss
• Write KQL tailored to your environment
• Recommend containment steps aligned to policy
• Analyze rare events against organizational baselines
• Highlight misconfigurations or toxic permission combinations.

This democratizes security expertise and reduces dependency on a handful of senior analysts.

Security outcome:

Every analyst operates with senior-level insight, improving consistency and resilience across shifts.

Cross-System Response Through Integrated SOAR + XDR Actions

SOAR automation (Sentinel) and live response (XDR) now function as a single response layer. This means that a Sentinel rule can detect suspicious service creation, and XDR can automatically isolate the device. Or a high-risk identity action can trigger both an Entra Identity Protection policy and a Sentinel playbook.

Security outcome:

Rapid, coordinated containment across identity, endpoint, cloud, and network layers.

2. The Operational Lens: SOC Efficiency, Simplicity & Scale

A Single Portal for Detection, Investigation & Response

Portal fragmentation has historically been one of the biggest sources of inefficiency in SOCs.

Analysts bouncing between the Sentinel and Defender portals, Entra ID, Azure Monitor, and various third-party consoles slowed investigations and created inconsistencies.

The unified portal eliminates this and dramatically reduces friction across Tier 1, Tier 2, and Tier 3 workflows.

Operational outcomes:

• One investigation experience 
• One alert/incident queue
• One timeline
• One query/search interface
• One automation panel

Unified Incident Management Aligned to Clear SLAs

SOC leads can now enforce:

• One SLA time
• One triage flow
• One escalation model
• One queue for analysts to prioritize

No more reconciliation between Sentinel incidents and Defender incidents.

Everything lands in one operational funnel.

Operational outcome:

Standardized Entity Models: Devices, Users, Apps & Resources

One of the most underestimated improvements is unified asset and identity views.

Whether a device is onboarded via Defender for Endpoint or logs originate via Sentinel agents, it appears as a single entity. The same applies to users, applications, and cloud resources.

Operational outcomes:

• Reduced duplication in investigations
• More accurate entity timelines
• Improved analyst confidence
  
  

Automation Integrated Where Analysts Live

Instead of manually triggering a Sentinel playbook or jumping between Logic Apps and Defender, analysts can now:

• Launch SOAR playbooks
• Execute XDR actions
• Apply conditional access controls
• Trigger private scripts

…all without leaving the incident pane.

Operational outcome:

Faster Analyst Ramp-Up and Lower Training Overheads

With a unified portal, training new staff becomes dramatically simpler.
Previously, analysts needed to learn Sentinel, MDE, MDI, MDO, Entra ID, Azure Monitor, and Defender Portal(s).

Now, one interface drives 80% of daily workflows.

Operational outcome:

Faster onboarding, reduced training cost, and improved SOC maturity.

3. The Commercial Lens: Lower Cost, Higher ROI & Better Business Outcomes

Greater ROI From Sentinel Data Ingestion

Sentinel’s great cost driver is log ingestion. The unified portal ensures that every gigabyte of data ingested delivers more value because it now enhances XDR detection and response, not just SIEM analytics. You effectively get:

• More correlations per dollar
• More AI assistance per dollar
• More insight per incident
• More accurate investigations per log source

Commercial outcome:

Labour Efficiency = Reduced SOC Cost

SOC labour is expensive. Anything that saves analyst time directly reduces cost. The unified model improves:

• MTTR (faster response)
• MTTD (faster detection)
• Analyst throughput
• Analyst confidence
• Case closure rates

Even a 10-20% efficiency improvement can translate into significant financial benefits for medium- to large-sized SOC teams.

Commercial outcome:

Lower Risk Exposure and Lower Cost of Incidents

The financial impact of a breach is enormous and can include downtime, regulatory exposure, IR engagement, and reputational loss. By improving the detection surface and reducing dwell time, the unified model helps:

• Prevent incidents from escalating
• Reduce the number of compromised assets
• Shorten containment windows

Commercial outcome:

Better Alignment with Hybrid & Multi-Cloud Strategies

Sentinel remains the ingestion engine for AWS, GCP, Palo Alto, Cisco, Zscaler, OT, and more.

Now this data enriches the XDR experience without needing:

• Additional XDR agents
• Third-party cross-cloud analytics solutions
• Multiple vendor contracts

Commercial outcome:

End-to-end SecOps visibility across ALL clouds without massive added spend.

Final Thoughts

The migration of Sentinel into the unified Defender XDR SecOps model is more than just a product transition; it’s a redesign of how detection and response operates across the enterprise. Through the security lens, organizations gain deeper visibility, earlier detection, and faster response. Through the operational lens, SOC teams benefit from unified workflows, consistent investigations, richer automation, and reduced friction. Through the commercial lens, businesses see stronger ROI, greater analyst productivity, and reduced breach impact.

LevelBlue is your trusted partner for every stage of your Microsoft Security journey. We help clients to maximize the return on their Microsoft security investments and meet you wherever you are on your cyber roadmap. Our “Accelerator” programs for Defender XDR and Sentinel can help your organization to position itself to take advantage of the full range of benefits on offer via the migration of Sentinel to the Unified Defender XDR SecOps Portal, in time for Microsoft’s July 2026 cutoff.