EDR and antivirus aren't competitors — they're different layers of endpoint protection: antivirus blocks known malicious files by signature, while EDR detects attacks by behavior and provides tools for investigation and response. One doesn't replace the other; in practice, they're used together.
This article covers one of the questions from the full guide "What Is EDR and How to Choose One".
What fundamentally sets the two approaches apart
In short: antivirus answers the question "is this a malicious file?" while EDR answers "what's happening on this endpoint, and could it be an attack?"
- Antivirus relies primarily on signatures and heuristics, blocking files that are already in its databases or resemble known samples.
- EDR continuously collects telemetry (processes, network connections, file and registry access), looks for suspicious behavior, and retains an event history for analysis.
What antivirus catches vs. what EDR catches
Antivirus handles widespread known threats well — malicious attachments, trojans, worms that already have a signature. It's a fast, low-cost baseline layer.
EDR covers what signatures miss:
- fileless attacks, where the adversary operates through memory and scripts;
- abuse of legitimate system utilities (living-off-the-land techniques);
- lateral movement and persistence within the infrastructure;
- chains of actions that look harmless individually but add up to an attack together.
Why they're used together
Antivirus and EDR complement each other: antivirus cheaply filters out the flow of known threats, while EDR provides visibility and response where signatures fall short. Dropping antivirus would flood analysts with noise from commodity threats, and dropping EDR would leave the infrastructure blind to targeted attacks.
In a mature security setup, both layers work together, with events feeding into a SIEM or XDR for a unified picture.
When antivirus alone isn't enough
Antivirus alone stops being sufficient as soon as your threat model includes targeted attacks and a human adversary, not just commodity malware. Signs it's time to deploy EDR:
- the company holds valuable data and is an attractive target for targeted attacks;
- you need the ability to investigate incidents, not just log detections;
- fast response is required — host isolation, process termination;
- there's a requirement to build or grow an in-house SOC.
Side-by-side comparison
Here's a quick summary of the key differences:
- How it works. Antivirus — signatures and heuristics; EDR — behavioral analysis of telemetry.
- What it detects. Antivirus — known malware; EDR — targeted and fileless attacks, abuse of legitimate tools.
- Response. Antivirus — blocks and removes the file; EDR — isolates the host, terminates processes, collects artifacts.
- Investigation. Antivirus — essentially none; EDR — a full event timeline.
- Who needs it. Antivirus — everyone, as a baseline layer; EDR — organizations facing targeted-attack risk with a team to investigate them.
Does EDR replace antivirus
No — EDR doesn't replace antivirus, it works on top of it. Antivirus remains a fast, low-cost filter for commodity threats, while EDR adds behavioral visibility and response for what that filter misses. Dropping either layer weakens your defenses: without antivirus, analysts drown in noise; without EDR, the infrastructure is blind to targeted attacks.
Practice the difference hands-on
The easiest way to understand the difference is on real telemetry. In the BI.ZONE EDR courses, you work through events and alerts on isolated lab environments, see how behavioral detection catches what a signature engine misses, and apply response actions. You can explore the product's capabilities on the BI.ZONE EDR page, and get a full overview of the category in the "What Is EDR" guide.