What Is the Difference Between Antivirus and EDR?

How Antivirus Works

Traditional antivirus:

1. Maintains a database of known malware signatures
2. Scans files against that database
3. Blocks or quarantines matches

The limitation: It only catches malware someone has seen before. New malware, modified malware, or fileless attacks slip through.

Antivirus is reactive. The bad guys create new malware; security vendors eventually add it to their databases; your antivirus eventually gets the update. There's always a gap.

How EDR Works

Endpoint Detection and Response:

1. Monitors endpoint behaviour continuously
2. Detects suspicious activity patterns
3. Correlates events across your environment
4. Enables investigation and response
5. Can isolate compromised endpoints

The advantage: EDR doesn't need to recognise specific malware. It recognises malicious behaviour—unusual process execution, suspicious network connections, credential access attempts.

EDR catches:

• Zero-day malware (never seen before)
• Fileless attacks (no malware file to scan)
• Living-off-the-land attacks (using legitimate tools maliciously)
• Lateral movement (attackers moving through your network)

The Practical Differences

Real World Example

Antivirus scenario: Attacker sends malware antivirus doesn't recognise. File runs. Antivirus does nothing. Attack succeeds.

EDR scenario: Same malware runs. EDR sees the process spawn suspicious child processes, attempt to disable security tools, and connect to a known command server. EDR alerts, isolates the endpoint, and gives you the full activity chain to investigate.

Do You Still Need Antivirus?

EDR typically includes or replaces traditional antivirus. Modern EDR platforms combine:

• Signature-based detection (like antivirus)
• Behaviour-based detection
• Machine learning models
• Threat intelligence
• Response capabilities

You don't run antivirus AND EDR separately. EDR is the evolution.

What About MDR?

MDR (Managed Detection and Response) adds human expertise:

• EDR is the technology
• MDR is EDR plus a security team monitoring and responding

For most SMEs, MDR makes more sense than raw EDR. You get the technology plus experts who know what to do when it alerts.

Our Recommendation

For business use, EDR (or better, MDR) is now the baseline:

• Antivirus alone isn't adequate against modern threats
• EDR provides the visibility and response capability you need
• MDR adds expertise most SMEs don't have in-house

We include MDR in our managed services. 24/7 monitoring by a security operations centre, with human-led response when threats are detected.