What Is Endpoint Detection and Response (EDR)?

EDR — Endpoint Detection and Response — is the category of security tooling that replaced traditional antivirus as the standard for business endpoint protection. Where antivirus matches known malware signatures, EDR watches for malicious behavior patterns and gives responders the ability to investigate and contain incidents on endpoints. The shift has been broad: traditional antivirus alone is no longer adequate for business environments. Here's what EDR actually does, how it differs from antivirus, and what to look for in a deployment.

The Limits of Traditional Antivirus

Traditional antivirus works by matching files against signatures of known malware. The model worked well for decades when malware was relatively stable and threat researchers could keep signature databases current. The model breaks down against modern threats:

• Polymorphic malware changes its signature with every infection, evading signature databases
• Living-off-the-land attacks use legitimate system tools (PowerShell, WMI, certutil) without dropping detectable malware
• Fileless attacks operate entirely in memory without writing files to disk
• Zero-day exploits target vulnerabilities before signatures exist
• Ransomware spreads faster than signature updates can be distributed

Antivirus still catches known threats — that hasn't gone away. But the percentage of real attacks it catches has declined steadily as attackers have evolved.

What EDR Adds

EDR addresses these gaps with a fundamentally different approach:

• Behavioral detection — watches for suspicious behavior patterns rather than just matching files. Process injection, credential dumping, unusual PowerShell activity, lateral movement attempts get flagged regardless of whether the underlying tool is known malware.
• Endpoint telemetry — continuous collection of detailed activity data — process creation, network connections, file operations, registry changes — enabling investigation of what happened on the endpoint
• Incident reconstruction — ability to look back at what happened on an endpoint, trace the attack path, and understand the scope
• Response capabilities — isolate compromised endpoints, kill malicious processes, rollback changes, collect forensic artifacts
• Threat hunting — proactive search for indicators of compromise across the endpoint fleet
• Integration with broader security tooling — feeding telemetry into SIEM platforms, correlating with identity and network events

The EDR Vendor Landscape

Major EDR platforms in current SMB and mid-market deployment:

• CrowdStrike Falcon — market leader, strong detection, premium price
• SentinelOne — competitive detection with autonomous response capabilities
• Microsoft Defender for Endpoint — strong product, particularly valuable for Microsoft 365 E5 customers where it's bundled
• Sophos Intercept X — strong SMB-focused offering
• Cisco Secure Endpoint — for Cisco-centric environments
• Cybereason, Trend Micro, Symantec/Broadcom — additional credible options

For SMB and mid-market businesses, the choice often comes down to existing platform investments (Microsoft Defender for Endpoint is hard to beat if you have E5), management model preferences (some EDR vendors require more in-house expertise than others), and budget.

EDR vs. MDR

EDR is the technology; MDR (Managed Detection and Response) is EDR delivered as a service with human analyst review. For most SMBs, MDR is the right consumption model because:

• EDR generates alerts that need human investigation; without analyst capacity, alerts pile up unaddressed
• Effective threat hunting requires expertise most SMBs don't have internally
• 24/7 coverage requires staffing that doesn't scale at SMB volume
• The MDR provider's threat intelligence and detection content updates benefit all their customers

The decision between EDR and MDR comes down to whether you have analyst capacity internally. If yes, EDR alone is fine. If no, MDR is the right model.

Deployment Considerations

EDR deployments are typically straightforward — lightweight agent installed on each endpoint, with cloud-based management — but a few things to verify: agent compatibility with your endpoint OS mix (Windows, Mac, Linux, mobile), performance impact on legacy hardware (typically minimal but worth confirming), integration with existing identity and SIEM platforms, retention period for telemetry data, and reporting capability for compliance and operational use. A conversation with our team can help scope which EDR or MDR option fits your environment.