Extended detection and response (XDR) is a security approach that correlates telemetry from endpoints, network, email, cloud and identity systems in one platform to detect and stop attacks.
How XDR works
XDR grew out of endpoint detection and response (EDR). EDR sees only what happens on computers; attacks, however, move through email, user accounts, cloud services and the network. An XDR platform ingests data from all these sources, normalises it and links related events into a single incident – for example a phishing email, a malicious attachment opened on a laptop, a suspicious login to the cloud and data upload to an unknown server. The term was popularised by Palo Alto Networks in 2018 and has since been adopted by most large security vendors.
Two variants exist: native XDR, built from one vendor’s own products, and open XDR, which integrates third-party tools.
XDR vs. SIEM
A SIEM collects logs from almost any source and is flexible but needs significant tuning and engineering. XDR is narrower but comes with ready-made detections, correlation and response actions – isolating a host, disabling an account, deleting an email – across integrated products. Many organisations use both: XDR for detection and response, SIEM for long-term retention, compliance and custom analytics.
Why XDR matters
Security teams are overloaded with alerts from separate tools. By correlating signals, XDR reduces noise, shortens investigation time and helps smaller teams or a SOC respond faster. Telemetry from multiple layers also supports threat hunting.
Things to consider
- Check which data sources are really integrated and how deep the response actions go.
- Beware of vendor lock-in with native XDR.
- XDR still needs skilled analysts or a managed service (MDR) to act on its findings.
