In today’s threat landscape, endpoint protection is more critical than ever. However, many IT professionals and business stakeholders are still confused by the differences between traditional antivirus (AV) and modern Endpoint Detection and Response (EDR) solutions. This blog post aims to clear the fog surrounding these technologies, highlighting their differences, their complementary roles, and why understanding both is key to building a secure endpoint defence strategy.

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What is Antivirus (AV)?

Antivirus software has been a foundational part of endpoint protection for decades. Traditional AV is designed to:

  • Detect known malware using signature-based detection.
  • Quarantine or delete malicious files.
  • Provide real-time protection by scanning files and processes.

Key Characteristics:

  • Signature-based: Relies on known patterns (“signatures”) of malicious code.
  • Lightweight: Typically uses fewer system resources.
  • Reactive: Focuses on identifying and stopping known threats.

While traditional AV still plays a role in endpoint security, its reactive nature and reliance on known signatures are less effective against modern, evolving threats like fileless malware, zero-days, and advanced persistent threats (APTs).

What is Endpoint Detection and Response (EDR)?

EDR is a newer, more advanced security solution focused on continuous monitoring and response. Unlike AV, EDR is designed to:

  • Continuously monitor endpoint activities.
  • Detect abnormal behaviours and suspicious activities.
  • Investigate potential threats using telemetry and forensics.
  • Provide response capabilities such as isolating infected devices or terminating processes.

Key Characteristics:

  • Behaviour-based: Uses analytics and heuristics to identify suspicious activity.
  • Rich telemetry: Collects detailed data for analysis.
  • Proactive: Detects and responds to unknown threats in real time.

EDR tools are built with the assumption that breaches will happen. The goal is to detect, contain, and respond quickly to reduce the impact.

Side-by-Side Comparison

Feature Antivirus (AV) Endpoint Detection and Response (EDR)
Detection Method Signature-based Behaviour-based and heuristic
Threat Coverage Known malware Known + unknown threats
Resource Usage Generally lightweight More resource-intensive
Real-Time Protection Yes Yes
Forensics / Threat Hunting No Yes
Response Capabilities Quarantine, Delete Isolate host, Kill process, Alert admin
Visibility into Endpoint Limited Extensive
Ideal For Basic malware protection Advanced threat detection & response

Why the Confusion?

Much confusion between AV and EDR comes from overlapping features and marketing jargon. Many modern AV products have incorporated some form of behavioural analysis or real-time monitoring, blurring the line between them. Similarly, some EDR platforms include antivirus-like protections as part of their feature set.

However, the key distinction is depth and intent:

  • AV is about the prevention of known threats.
  • EDR is about detection and response to advanced, unknown, and evolving threats.

Another point of confusion is terminology. Vendors often label their solutions as “Next-Gen AV” or “XDR” (Extended Detection and Response), which adds complexity. While next-gen AV may include machine learning and behavioural analysis, it lacks the complete forensic and response toolkit that defines a proper EDR solution.

Real-World Analogy

Think of your endpoint as a house:

  • Antivirus is like a lock on the front door. It prevents known burglars from getting in.
  • EDR is a surveillance system with motion detectors, cameras, and remote police access. It identifies when someone’s in the house who shouldn’t be, and it can trigger an alarm, lock down the property, or notify the authorities.

Both are important, but one reacts to intrusions with far more intelligence and context.

Do You Need Both?

Absolutely. AV and EDR serve different roles in a layered security strategy:

  • AV is essential for stopping the “low-hanging fruit” – known threats that still account for many attacks.
  • EDR is critical for advanced threat protection, incident investigation, and response automation.

Organizations that rely solely on antivirus are often blind to sophisticated threats already residing within their environment. Conversely, relying solely on EDR without AV could lead to unnecessary resource consumption and missed opportunities to stop commodity malware at the gate.

EDR in Action: A Simple Scenario

Let’s say an employee clicks on a phishing email and opens a malicious Excel macro that downloads a remote access tool (RAT).

  • Antivirus software might catch the RAT if its signature is known. However, if it’s a new variant, it might go undetected.
  • EDR monitors the Excel process and notices it spawns PowerShell scripts and unusual outbound traffic. It flags this behaviour, alerts the SOC team, and isolates the host before further compromise.

EDR doesn’t just stop threats – it provides insight, context, and response tools.

Conclusion

The difference between EDR and antivirus boils down to scope and sophistication. Antivirus protects against what is known; EDR protects against what is happening.

The takeaway for beginners to intermediate IT professionals is that EDR is not a replacement for AV, but an essential evolution. Embrace both in your security stack. When properly configured and monitored, they complement each other and significantly reduce your attack surface.

Security is no longer about keeping threats out entirely – it’s about visibility, response, and resilience when they get in. Knowing when to use a lock and when to install cameras is part of being a savvy security professional in today’s digital world.

Steve Labeau – Principal Consultant / Blogger