Is traditional antivirus enough? Learn why Endpoint Detection and Response (EDR) is essential for modern business cyber security.
Most Melbourne businesses running Windows have some form of antivirus. The question is whether that antivirus is still doing the job it needs to do — or whether it is providing a false sense of security against threats that have evolved significantly beyond what signature-based detection can catch.
The short answer: traditional antivirus, on its own, is no longer sufficient. Here is why, and what EDR provides instead.
What Traditional Antivirus Does
Traditional antivirus works by maintaining a database of known malware signatures — unique fingerprints of known malicious files. When a file is accessed or executed, the antivirus compares it against the signature database. If it matches a known threat, it is blocked or quarantined.
This approach works well against known malware — threats that have been catalogued and added to the signature database. It is fast, low overhead, and effective for the threat landscape of 2005.
The problem is that it is 2026, and the threat landscape has changed fundamentally.
Why Signature-Based Detection Fails Against Modern Threats
Polymorphic and Fileless Malware
Modern malware is frequently polymorphic — it modifies its own code to produce a different signature each time it executes, evading signature matching. Fileless malware does not write to disk at all, operating entirely in memory using legitimate system tools (PowerShell, WMI, living-off-the-land binaries). There is no file to scan.
Zero-Day Exploits
A zero-day exploit targets a vulnerability that has not yet been patched or catalogued. By definition, there is no signature for a zero-day threat — it has not appeared in the wild before. Traditional antivirus is blind to it.
Legitimate Tools Used Maliciously
Ransomware operators frequently use legitimate Windows tools (PsExec, Cobalt Strike, Mimikatz) that are not intrinsically malicious. A file that is a legitimate Windows administration tool cannot be blocked by signature — the antivirus cannot distinguish between a legitimate admin using PsExec and a ransomware operator using it to move laterally across the network.
Evasion Techniques
Attackers test their malware against commercial antivirus products before deploying it against targets. Malware that evades the major AV engines is widely available.
What EDR Is
Endpoint Detection and Response (EDR) is a security technology that continuously monitors endpoint behaviour — what processes are running, what files are being accessed, what network connections are being made, what registry changes are occurring — and uses this behavioural data to detect and respond to threats.
Rather than asking “does this file match a known bad signature?”, EDR asks “is this behaviour consistent with malicious activity?”
Key EDR capabilities:
Behavioural analysis: Detects patterns consistent with attack techniques — credential dumping, lateral movement, persistence mechanisms — regardless of whether the specific tool used has been seen before.
Threat hunting: Security analysts can query EDR telemetry to search for indicators of compromise across all endpoints, retroactively identifying threats that may have been present for weeks or months before detection.
Automated response: When a threat is detected, EDR can automatically isolate the affected endpoint from the network, terminate malicious processes, and roll back malicious changes — without waiting for human intervention.
Investigation timeline: EDR maintains a detailed activity log for each endpoint, allowing security teams to reconstruct exactly what happened during an incident — which files were accessed, what credentials were used, how far the attacker moved.
EDR vs Antivirus: The Key Differences
| Capability | Traditional AV | EDR |
|---|---|---|
| Known malware detection | Yes (signatures) | Yes (signatures + behaviour) |
| Unknown/zero-day threats | No | Yes (behavioural detection) |
| Fileless malware | No | Yes |
| Living-off-the-land attacks | No | Yes |
| Automated response | Limited | Yes (isolation, rollback) |
| Threat hunting | No | Yes |
| Incident investigation | No | Yes (full timeline) |
| Overhead | Low | Low-medium |
MDR: Managed Detection and Response
EDR generates significant telemetry and requires security expertise to interpret effectively. For Melbourne SMBs without an internal security team, Managed Detection and Response (MDR) services pair EDR technology with 24/7 human security analyst coverage.
An MDR service:
- Monitors EDR alerts around the clock, including after hours and weekends
- Investigates suspicious activity to determine whether it is a genuine threat or a false positive
- Responds to confirmed threats — containing the incident, guiding remediation
- Provides regular reporting on threat activity and security posture
For most Melbourne SMBs, MDR is the practical delivery model for EDR capability — the technology without the people to monitor it provides only partial value.
Windows Defender: Is It Enough?
Microsoft Defender for Endpoint (included in Microsoft 365 Business Premium) is a legitimate EDR platform, not just antivirus. It provides:
- Real-time antivirus and anti-malware
- Behavioural detection
- Attack surface reduction rules
- Endpoint detection and response capability
- Integration with Microsoft Sentinel (SIEM) and Entra ID
For a Melbourne SMB using Microsoft 365 Business Premium, Defender for Endpoint configured correctly provides EDR capability at no additional cost beyond the M365 licence.
The caveat: Defender for Endpoint needs to be properly configured and monitored to provide its full value. The default out-of-box configuration is not optimal. Attack surface reduction rules need to be enabled, integration with the Microsoft 365 Defender portal needs to be active, and alerts need to be monitored.
Third-Party EDR Options for SMBs
Where Microsoft Defender is not preferred or additional capability is required:
CrowdStrike Falcon Go/Pro: Market-leading EDR platform. Strong detection capability, cloud-native architecture, low endpoint overhead. Falcon Go starts at approximately $8-15 per endpoint per month.
SentinelOne Singularity: Strong automated response capability, good for organisations wanting AI-driven autonomous response. Competitive with CrowdStrike at similar pricing.
Sophos Intercept X with MDR: Strong SMB positioning, straightforward management console, includes MDR option. Popular in the Australian MSP market.
Malwarebytes EDR: Lower entry price, suitable for very small businesses. Less feature-rich than enterprise-grade platforms.
The ACSC Position
The Australian Cyber Security Centre’s Essential Eight includes “patch applications” and “user application hardening” as controls — but does not specifically mandate EDR. However, the ACSC’s guidance on ransomware and malware protection consistently recommends behavioural detection and response capability beyond signature-based antivirus.
For businesses pursuing Essential Eight Maturity Level 2 or higher, EDR-class endpoint protection is effectively required to meet the intent of the controls even if not explicitly named.
CX IT Services deploys and manages EDR solutions for Melbourne businesses, including Microsoft Defender for Endpoint configuration, third-party EDR deployment, and MDR monitoring services. Book a Right Fit Call to assess your current endpoint protection and discuss the right approach for your business.
