Endpoint Detection and Response (EDR) for UK Businesses

Antivirus only stops threats it has already catalogued. EDR (Endpoint Detection and Response) watches what software actually *does* on a device, so a brand-new ransomware strain is caught the moment it starts encrypting files. That behavioural layer is now the baseline for serious managed cybersecurity, and for most UK SMEs it is already paid for inside Microsoft 365 Business Premium.

What is EDR and how is it different from antivirus?

EDR is software installed on every endpoint that continuously records process events, file changes, registry edits, memory operations, and network connections, then analyses that telemetry against detection rules, threat intelligence, and machine-learning models. Antivirus matches files to a signature database; EDR judges behaviour, so it catches threats no signature exists for yet.

Traditional antivirus protects against threats it has already seen. It struggles with novel variants, polymorphic malware, and fileless attacks that never write a file to disc. EDR closes those gaps by focusing on activity rather than appearance — see our full breakdown of EDR vs antivirus for the technical detail.

How does EDR detect and respond to threats?

An EDR agent on each device captures telemetry and streams it to a central platform, where three layers run in parallel: known indicators of compromise (IOCs) are matched, behavioural analytics flag suspicious patterns, and machine-learning models surface anomalies that rules alone would miss. Confirmed threats trigger automated response.

When suspicious behaviour is identified, the platform can quarantine a file, terminate a malicious process, isolate the compromised device from the network, or roll back changes made by ransomware. Because EDR retains historical telemetry, analysts can investigate an incident retrospectively rather than guessing what happened.

What EDR detects that antivirus cannot:

• Fileless malware — operating entirely in memory using legitimate system tools
• Living-off-the-land attacks — abusing pre-installed binaries like PowerShell
• Credential theft and lateral movement — harvesting credentials from memory and spreading across the network
• Zero-day exploits — attacks against unpatched vulnerabilities
• New ransomware variants — strains created daily, with no existing signature

Why do UK SMEs need EDR?

UK SMEs need EDR because most modern attacks are designed to defeat signature-based antivirus. According to the UK Government's Cyber Security Breaches Survey 2025, "43% of UK businesses experienced a cybersecurity breach or attack in the past twelve months" — many using fileless techniques and novel malware that only behavioural detection catches.

The financial exposure is real: the average cost of a data breach for UK organisations was £3.58 million according to IBM's 2024 Cost of a Data Breach report. Yet only "14% of UK businesses have a formal incident response plan" (Cyber Security Breaches Survey 2025), so detections often pile up with no one to act on them. EDR without a response process is a half-measure.

Is Microsoft Defender for Business a real EDR?

Yes. For most UK SMEs, Microsoft Defender for Business is the primary EDR platform. It is included in Microsoft 365 Business Premium at no additional licence cost and delivers behavioural detection, attack surface reduction (ASR) rules, endpoint isolation, and integration with Microsoft's global threat intelligence network.

Defender for Business is significantly more capable than the consumer Windows Defender built into Windows 10 and 11. ASR rules go a step further than detection — they stop specific attack techniques from executing at all, blocking attacks before EDR response is even needed. EDR tools like Defender for Business also satisfy the malware protection control required for Cyber Essentials certification.

When does managed detection add value on top of EDR?

EDR tools generate alerts; someone has to read, judge, and act on them. For businesses in regulated sectors, with elevated risk, or seeking MDR-level coverage, AMVIA layers its in-house 24/7 SOC on top of Microsoft Defender for Endpoint — reviewing every suspicious detection, giving clear remediation guidance, and taking direct containment action.

This human-in-the-loop approach is what catches persistent threats — backdoors, remote access trojans, slow lateral movement — that an unattended tool would log and forget. EDR is the technology; managed detection and response is the service that makes it count. For the distinction in full, read MDR vs EDR.

How much does managed EDR cost?

For most UK SMEs, the EDR engine itself carries no extra licence cost — Microsoft Defender for Business is included in Microsoft 365 Business Premium at approximately £16.90 per user per month (Microsoft UK). The cost you are buying beyond the licence is the management: deployment, tuning, alert investigation, and response.

• Microsoft Defender for Business — included in M365 Business Premium (~£16.90 per user per month)
• AMVIA managed detection and response — priced per endpoint per month

EDR should cover every managed endpoint — laptops, desktops, and servers — with no unmanaged device left holding network access.

What does AMVIA's managed EDR include?

AMVIA deploys and manages EDR for UK SMEs as part of its endpoint security service. We configure Microsoft Defender for Business, deploy attack surface reduction rules, monitor alerts through our SOC, investigate significant detections, and take containment action when threats are confirmed. Monthly reports give you clear visibility of protection status and incidents.

Implementation checklist we work through:

• EDR deployed on all managed endpoints — laptops, desktops, servers
• ASR rules configured to block common attack techniques
• Alerts monitored and investigated, not just collected
• Automated containment configured for high-confidence detections
• Coverage verified — no unmanaged devices with network access
• Monthly status and detection report reviewed with you

For a deeper technical view of the underlying detection technology, see endpoint detection and response.