Cyber threats are evolving in sophistication and scale. From phishing emails to credential theft, from privilege escalation to cloud data exfiltration, attackers rely on chained techniques that slip past siloed defenses. Modern security operations demand a unified approach—one that combines Extended Detection and Response (XDR) with Security Information and Event Management (SIEM), enriched by intelligence and AI. And that’s exactly where Microsoft Defender XDR and Microsoft Sentinel converge today.
Why Defenders Still Struggle
Siloed security leads to gaps in coverage:
Think about an Business Email Compromise (BEC) attack for instance:
1. User opens a phishing email.
2. Endpoint is exploited.
3. Attacker escalates privileges.
4. Domain is compromised.
5. Backups are deleted, files encrypted, and sensitive data exfiltrated.
Each stage might trigger alerts in different tools—email gateways, endpoint protection, identity services, cloud access brokers. But without correlation, the pieces don’t connect.
Defender XDR + Sentinel: One Hunting Platform
Before we dive into the advantages of a unified hunting platform, it is crucial to understand how Incident Analytics works. I have split up the categories in Event, Correlated Event (Alert), Alert + Alert (Incident), and Algorithm:
Microsoft has taken a big step forward: Sentinel is now integrated into the Defender XDR portal.
This unification changes the hunting game. Some advantages of the Defender XDR integration:
- Single Incident Queue: Incidents in Sentinel and Defender XDR are synchronized bi-directionally. SOC analysts can triage alerts, entities, and anomalies in one place.
- Reduced Context Switching: No more flipping between Azure Sentinel and Defender—analysts pivot directly from detection to hunting to investigation.
- Retirement of Legacy Portal: The Azure Sentinel interface will be deprecated by July 2026, making Defender XDR the single pane of glass.
More information can be found here: https://learn.microsoft.com/en-us/azure/sentinel/microsoft-sentinel-defender-portal
Why Threat Hunting Matters
Alerts are only part of the story. Advanced hunting lets analysts ask the questions tools may miss:
- Are inbox rules redirecting email externally?
- Is there suspicious lateral movement between endpoints?
- Are users authenticating from impossible geographies?
The benefit? Hunting is hypothesis-driven, proactive, and helps Tier 1/2 SOC analysts neutralize up to 80% of threats before escalation.
Kusto Query Language: The SOC’s Microscope
At the core is Kusto Query Language (KQL)—a scalable way to query telemetry across Defender XDR and Sentinel.
Example: Hunting a Business Email Compromise (BEC):
EmailEvents
| where Subject contains “invoice”
| where SenderFromDomain !in (“yourdomain.com”)
| project Timestamp, SenderFromAddress, RecipientEmailAddress, Subject
Steps an analyst might trace:
1. Detect when an user clicks a phishing link.
2. Identify inbox rules forwarding mail externally.
3. Spot fraudulent invoice attempts.
4. Correlate with endpoint and identity telemetry to confirm compromise.
Defender Threat Intelligence: Smarter Hunting at Scale
Hunting isn’t just about telemetry—you need intelligence. Defender Threat Intelligence (MDTI) feeds hunters with massive, continuously updated datasets:
Here’s the big update: MDTI is now included for many Microsoft customers at no additional cost when access via Defender XDR or Sentinel’s new data lake. The announcement can be found here: https://techcommunity.microsoft.com/blog/defenderthreatintelligence/mdti-is-converging-into-microsoft-sentinel-and-defender-xdr/4427991
- Connector & Rules Free: Customers can use MDTI data connectors and analytics rules without a premium license.
- Ingestion Costs Apply: Data ingested into the ThreatIntelligenceIndicator table still generates ingestion charges.
- Premium API Access: For raw intelligence access (custom apps, enrichment pipelines), the MDTI Premium license is still required.
Sentinel Data Lake: AI-Ready Hunting
Sentinel’s new Data Lake architecture is a game-changer.
- AI-Optimized Storage: Centralizes logs from 350+ connectors without traditional storage constraints.
- MDTI Built-In: Defender Threat Intelligence data is automatically available—no extra license needed for core hunting use cases.
- Long-Term Retention: Enables forensic and compliance queries years after incidents.
- Cost Efficiency: Reduces overall SIEM TCO while providing richer AI-driven detections.
Javier and David did a Ninja Show Recording session to cover an AMA-style about the new data lake architecture: https://www.youtube.com/embed/25-dUtbwiRw?si=_LHNauDUa6pBG3tC
Security Copilot: The AI Assistant in Your SOC
Last but not least, Microsoft Security Copilot supercharges analysts:
- Summarizes incidents in seconds.
- Suggests remediation steps based on real-world TTPs.
- Generates executive-ready reports automatically.
- Identifies vulnerabilities and prioritizes fixes.
This isn’t replacing analysts—it’s scaling them.
Wrapping Up
Modern attackers rely on chaining techniques across identities, endpoints, and cloud services. Microsoft’s unified approach—Defender XDR + Sentinel inside one portal, enriched with MDTI and AI-driven hunting tools like Security Copilot—arms defenders with the context, speed, and intelligence to match them.
Advanced hunting isn’t optional anymore. It’s how defenders stay ahead.
