Defining Extended Detection and Response
Extended detection and response (XDR) is a security approach that unifies telemetry from multiple security domains (endpoints, networks, cloud workloads, email, and identity systems) into a single platform for detection, investigation, and response. The goal of XDR is to break down the silos between traditional point security products and provide security teams with a coherent, cross-domain view of threats.
The term was first popularised around 2018 by Palo Alto Networks, but the concept reflects a broader industry recognition that managing separate EDR, NDR, SIEM, and email-security tools creates operational friction, detection blind spots, and analyst fatigue. XDR aims to solve these problems by integrating detection and response across all security-relevant telemetry sources.
The Problem XDR Solves
To understand why XDR emerged, consider the typical security stack of a mid-to-large enterprise:
- An EDR platform monitoring endpoints
- An NDR or IDS/IPS solution monitoring network traffic
- A SIEM aggregating logs from dozens of sources
- An email security gateway filtering inbound messages
- A cloud security posture management (CSPM) tool for cloud environments
- A UEBA platform for user behaviour analytics
- A SOAR platform for response automation
Each of these tools generates its own alerts, uses its own data model, and provides its own investigation interface. When a sophisticated attack spans multiple domains, as most do, analysts must manually pivot between consoles, correlate events across different data formats, and reconstruct the attack timeline from fragmentary evidence.
This approach has three critical weaknesses:
- Detection gaps: Threats that manifest as individually benign events across multiple domains may never trigger an alert in any single tool. Only when these events are correlated does the malicious pattern become apparent.
- Alert fatigue: Each tool generates alerts independently, often producing thousands per day. Without cross-domain correlation, analysts cannot efficiently separate true threats from noise.
- Slow investigation: Pivoting between multiple consoles and manually correlating data extends mean time to respond (MTTR), giving adversaries more time to achieve their objectives.
XDR addresses all three weaknesses by consolidating telemetry and detection logic into a unified platform.
Native XDR vs Open XDR
The XDR market has evolved into two distinct approaches, each with different trade-offs:
Native XDR
Native XDR platforms (sometimes called "closed" XDR) provide first-party sensors and agents for every telemetry domain they cover. The same vendor supplies the endpoint agent, network sensor, email-security integration, and cloud connectors. All data flows into a single, purpose-built analytics engine.
Advantages:
- Tight integration between telemetry sources with a consistent data model
- Simplified deployment and management: one vendor, one platform
- Improved detection logic that can use the specific telemetry format of each first-party sensor
Disadvantages:
- Vendor lock-in: adopting native XDR typically means replacing existing best-of-breed tools with the vendor's own offerings
- Coverage gaps if the vendor's sensors do not match the depth of dedicated point solutions in every domain
Open XDR
Open XDR platforms act as a unifying layer that ingests telemetry from existing third-party security tools. Rather than replacing your EDR, NDR, and email-security solutions, open XDR normalises their data into a common schema and applies cross-domain analytics on top.
Advantages:
- Preserves existing tool investments
- Flexibility to swap out individual components without replacing the entire detection platform
Disadvantages:
- Integration quality varies significantly depending on the third-party tools in use
- Normalisation can lose fidelity: subtle telemetry details that are meaningful for detection may be discarded during data transformation
- Higher operational complexity: you still manage multiple tools, plus the XDR layer
How XDR Differs from SIEM, EDR, and NDR
XDR is often confused with SIEM, or positioned as merely "EDR plus NDR." The distinctions are important:
XDR vs SIEM
- SIEM is a log-management and correlation platform. It collects logs from a wide range of sources and applies rules and statistical models to detect threats. SIEMs are powerful but require significant investment in log onboarding, rule writing, and tuning. They are also historically reactive: analysts search through logs after an alert rather than being proactively guided to threats.
- XDR collects telemetry rather than logs, providing deeper and more structured data. XDR platforms typically include pre-built detection logic and investigation workflows, reducing the customisation burden that SIEMs impose. XDR is also designed for response, not just detection, with native or integrated response capabilities across all domains.
XDR vs EDR
- EDR focuses exclusively on endpoint telemetry. It provides deep visibility into process activity, file operations, and endpoint-level network connections but has no native visibility into network traffic between hosts, email-borne threats, or cloud-infrastructure activity.
- XDR extends EDR's detection and response capabilities across additional domains, correlating endpoint events with network, email, identity, and cloud telemetry to provide a more complete threat picture.
XDR vs NDR
- NDR focuses exclusively on network traffic analysis. It excels at detecting lateral movement, command-and-control communications, and data exfiltration at the network layer but lacks visibility into endpoint-level processes and user-identity context.
- XDR incorporates NDR's network visibility alongside endpoint, identity, and other telemetry sources, enabling detection of threats that span multiple domains.
SenseOn's Approach to Unified Detection
SenseOn was designed from the ground up as a unified detection and response platform that avoids the compromises of both the native and open XDR approaches.
One Agent, Multiple Telemetry Domains
Instead of deploying separate agents for EDR and NDR (as most native XDR vendors require), SenseOn uses a single lightweight agent that simultaneously captures endpoint process telemetry, network flow metadata, and user-identity events. This architectural decision eliminates the integration layer ; there is no data normalisation or API-based correlation because all telemetry originates from the same sensor and shares a common data model from the moment of capture.
The Cross-Domain Correlation Methodology
SenseOn's detection engine does not rely on a single analytical approach. Every potential alert is evaluated by three independent AI methodologies:
- Supervised models trained on labelled datasets of known attack patterns
- Unsupervised models that detect statistical anomalies without prior knowledge of specific threats
- Deep-learning models that analyse sequences of events over time to identify complex attack behaviours
An alert is only surfaced when multiple models agree, which dramatically reduces false positives while maintaining high detection coverage.
Response Without Pivoting
Because all telemetry lives in a single platform, analysts can investigate and respond without pivoting between consoles. A network anomaly alert automatically includes the responsible endpoint process, the user account, and the full historical context, all in a single view. Response actions (process termination, endpoint isolation, user-account suspension) are available directly from the investigation interface.
Is XDR Right for Your Organisation?
XDR, or more precisely, the unified detection and response capability that XDR represents, is valuable for organisations that:
- Operate multiple security tools and struggle with correlation, integration, and alert fatigue
- Have a lean security team that cannot sustain the operational overhead of managing and correlating multiple point solutions
- Face sophisticated threats that span multiple domains and evade single-domain detection tools
- Want to reduce MTTR by providing analysts with cross-domain context and response capabilities in a single platform
The most important consideration is not whether a platform carries the "XDR" label, but whether it genuinely unifies telemetry, correlates detections across domains, and simplifies the analyst experience. Labels aside, that is the outcome every security team should be pursuing.
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