Traditional antivirus catches known malware by signature. Modern threats do not bother with malware. Here is what Endpoint Detection and Response actually adds.
Why Signature-Based AV Has a Ceiling
Signature-based antivirus compares files and processes against a database of known malicious patterns. It works well for malware families that have been catalogued. It fails completely against fileless attacks (malware that runs entirely in memory), living-off-the-land techniques (attackers using legitimate Windows tools like PowerShell and WMI for malicious purposes), and zero-day exploits. The majority of successful breaches in 2025 used techniques that traditional AV would not detect. This is not a criticism of AV — it is a description of the problem it was built to solve, and that problem has evolved.
What EDR Adds to the Endpoint
Endpoint Detection and Response tools record a continuous stream of endpoint telemetry: process creation, network connections, file system changes, registry modifications, and user activity. When a suspicious sequence of events occurs — a Word macro spawning a PowerShell process that makes an outbound network connection — the EDR detects the pattern even if no individual event is malicious. This behavioural detection catches attack chains that signature-based tools miss. The 'Response' part means the tool can isolate the endpoint, terminate processes, or roll back changes automatically or under analyst guidance.
Managed EDR vs Self-Managed
EDR tools produce a significant volume of alerts. Self-managed EDR at a company without a dedicated security operations capability generates alert fatigue — alerts go unreviewed or are dismissed without investigation. Managed Detection and Response (MDR) services pair the EDR tooling with a 24/7 SOC team that investigates, triages, and responds. For companies without internal security operations capability, managed EDR is significantly more valuable than an unmanaged deployment of the same technology.
The Platforms Worth Knowing
CrowdStrike Falcon and Microsoft Defender for Endpoint are the two dominant enterprise EDR platforms in 2026. Microsoft Defender is bundled in M365 Business Premium and Microsoft 365 E5 — if you have those licences, you may already have a capable EDR platform you are not fully deploying. CrowdStrike has broader cross-platform support and a more mature threat intelligence feed. For organisations already invested in the Microsoft stack, Defender for Endpoint is a logical first deployment; for everyone else, CrowdStrike is the most commonly deployed enterprise choice.
- Traditional AV fails against fileless attacks, living-off-the-land techniques, and zero-day exploits
- EDR detects malicious event sequences (attack chains) via behavioural analysis — not signature matching
- Unmanaged EDR generates alert fatigue — managed EDR (MDR) pairs the tool with a 24/7 SOC team
- Microsoft Defender for Endpoint may already be included in your M365 licence — verify deployment status