Endpoint Detection and Response (EDR) used to be enterprise-only technology. Five years ago, deploying it across an SME meant a six-figure project, a dedicated security analyst and a tool that looked like a Bloomberg terminal. Microsoft Defender for Business — included with Microsoft 365 Business Premium — has quietly closed most of that gap, and the SMEs that turn it on properly get a noticeably stronger security posture than businesses ten times their size did a few years ago.
What Defender for Business actually does
- Next-generation anti-malware on Windows, macOS, iOS and Android devices.
- EDR — behaviour-based detection of suspicious activity (ransomware patterns, credential theft, lateral movement).
- Automated investigation and remediation — Defender acts on common threats without waiting for a human.
- Attack surface reduction rules — blocks the techniques attackers use to get a foothold (Office macros, script-based attacks, credential dumping).
- Vulnerability management — continuous scan for missing patches and weak configuration, with prioritised guidance.
- Web content filtering — block phishing and malicious sites at the browser layer.
What to enable first
Out of the box, Defender does the minimum. The real value comes from a handful of policies that we apply on every deployment: enable all attack-surface-reduction rules in audit mode, then move them to block once you have triaged the noise. Turn on automated investigation at full automation. Enforce tamper protection so attackers cannot disable Defender from a compromised endpoint. Push Edge with SmartScreen and web filtering enabled. Onboard servers as well as workstations — most SMEs forget servers exist.
How it compares to third-party EDR
For the average SME, Defender for Business is now a credible alternative to dedicated third-party EDR products from vendors like SentinelOne, CrowdStrike or Sophos. The third-party products usually have better reporting consoles and stronger threat-hunting features — but those benefits only matter if you have someone watching the console. Most SMEs do not. Defender for Business, properly configured and bundled with a managed service, is the right answer for the large majority of SMEs we work with.
We deploy and manage Microsoft Defender for Business as part of our managed IT and managed security services. If you have Business Premium licences but are not sure whether Defender is doing anything useful, we offer a free 30-minute review.
