If you're running an SME, you've got a 1 in 2 chance of getting hit by a cyberattack. With 8.58 million instances of cybercrime affecting UK businesses in the past year alone, this isn't some distant threat - it's happening right now.
What most businesses don't realise is thinking they're too small to matter. You've got customer data, intellectual property, and bank details. That's valuable to attackers, and they often target smaller businesses who may have invested less in protection.
The cyber threat landscape is constantly evolving. It takes an average of 212 days to identify an attack and another 75 days to contain it. With 70% of successful breaches starting on endpoint devices - your laptops, desktops, and mobile devices - you can't afford gaps in your coverage.
One solution that delivers real protection is Microsoft Defender. If you're already using Microsoft 365, you probably have some version of it included. But here's what you need to understand: having the technology isn't the same as being protected. This guide explains what you actually have, what it does, and what's still missing.
What is Microsoft Defender?
Microsoft Defender is Microsoft's security software that protects your devices and email from cyber threats. It's not a single product - it's a family of tools that work together.
The two main components that matter for SMEs are:
Microsoft Defender for Endpoint: Protects your devices - laptops, desktops, servers, and mobile phones. It detects threats, investigates suspicious activity, and can automatically contain problems before they spread.
Microsoft Defender for Office 365: Protects your email and collaboration tools from phishing attacks, malware, and other threats that come through email.
When these tools work together, they create a security layer across your business. A suspicious email can trigger investigation of the device where it was opened. Unusual activity on a laptop can trigger review of that user's recent emails. This connected approach is more effective than isolated security tools.
Understanding What You Already Have
This is where most businesses get confused. What's included with your Microsoft 365 licence varies significantly, and what you can do with each version is quite different.
If You Have Microsoft 365 Business Premium
You already have Microsoft Defender for Business included at no additional cost. This is designed specifically for SMEs with up to 300 users and provides solid endpoint protection:
- Advanced virus and malware protection
- Detection of suspicious activity on your devices
- Automatic response to contain threats
- Identification of security vulnerabilities
- Works with Microsoft Intune if you use it for device management
This is significantly better than basic antivirus and provides genuine enterprise-grade protection. However, it does have some limitations compared to the versions designed for larger organisations with dedicated security teams.
If You Need More Advanced Protection
Larger organisations or those with specific compliance requirements might need Microsoft Defender for Endpoint P1 or P2. These enterprise versions offer deeper investigation tools, more sophisticated threat detection, and integration with advanced security systems.
For most SMEs, Defender for Business (included with Business Premium) provides the right level of technology. The question isn't whether you need more advanced software - it's whether you have the expertise to manage what you already have.
The Key Point About Licensing
The important thing to understand is that for most SMEs, the technology in Defender for Business is effective. Where many SMEs find challenges isn't with the software capability - it's with having someone to watch the alerts, investigate threats, and respond when something happens.
What Microsoft Defender Actually Protects
Microsoft Defender provides protection against the threats that actually matter to your business:
Email-Based Attacks: Phishing emails, malicious attachments, and dangerous links are blocked before they reach your users. The system checks every email in real-time and quarantines threats automatically.
Device Threats: Malware, ransomware, and viruses are detected on your laptops, desktops, and servers. When threats are found, the system can isolate infected devices to stop the problem spreading.
Compromised Credentials: The system monitors for unusual login attempts, access from unexpected locations, and other signs that someone's credentials may have been compromised.
Dangerous Websites: When employees click on links, Microsoft Defender checks the destination in real-time and blocks access to malicious sites.
USB and Device Risks: You can control which external devices (USB drives, external hard drives) can be used on your network, preventing data theft and malware introduction.
Suspicious Behaviour: The system watches for unusual patterns - someone accessing files they don't normally need, logging in at unusual hours, or downloading large amounts of data. These early indicators can help identify potential problems before they escalate.
The technology is sophisticated, but the concept is straightforward: protect the ways attackers typically get into your business and detect when something unusual is happening.
What Microsoft Defender Doesn't Do on Its Own
Here's what many businesses don't realise: Microsoft Defender detects threats and can contain them automatically. But it doesn't provide everything you need for complete protection.
No 24/7 Human Monitoring: The technology creates alerts around the clock. But who's watching those alerts at 3am on Saturday? Who investigates suspicious activity when your team is off? Microsoft Defender generates the warnings - it doesn't provide the security analysts to act on them.
No Expert Investigation: Complex threats require human expertise to understand what's really happening, assess the actual risk, and determine the right response. Automated tools help, but they can't replace experienced security professionals making judgment calls.
No Ongoing Tuning: Security systems generate thousands of alerts. Without proper tuning, you'll drown in false alarms while potentially missing real threats. Someone needs to continuously adjust the settings to balance catching genuine threats with avoiding alert fatigue.
No Incident Response Coordination: When a real security incident occurs, someone needs to coordinate the response across affected systems, users, and business functions. This requires dedicated resources and expertise that most SMEs don't have internally.
No Security Programme Management: Vulnerability assessments, security recommendations, policy updates, and compliance reporting all require ongoing attention. The technology provides the information, but someone needs to act on it.
This is the gap many SMEs face: excellent detection technology, but limited resources for watching, investigating, and responding. It's like having a burglar alarm but no monitoring service or response plan when it goes off.
What Complete Protection Actually Requires
Effective cyber security isn't just about technology. It's about combining the right tools with expert management. Here's what you need to make your Microsoft Defender investment truly protect you.
Start with the Technology Foundation
If you have Microsoft 365 Business Premium, you already have Defender for Business. Make sure it's properly configured and enabled across all your devices. If you don't have Business Premium, get it - the endpoint protection alone justifies the cost.
Add Microsoft Defender for Office 365 to protect your email. Email remains the primary way attackers get into businesses, making this protection essential rather than optional.
Address the Management Gap
This is where many SMEs find challenges. You need someone to:
Monitor continuously: Watch for genuine threats amongst thousands of routine security events, 24/7/365. Threats don't respect business hours.
Investigate effectively: When alerts trigger, determine if it's a real threat, understand the scope, and recommend appropriate action. This requires experience and security expertise.
Respond rapidly: Genuine threats need immediate response. Waiting until Monday morning to investigate a Friday evening alert gives attackers an entire weekend.
Tune appropriately: Reduce false positives while maintaining high detection rates. This requires expertise and understanding of your specific environment.
Manage the programme: Handle vulnerability assessments, implement security recommendations, update policies, and maintain compliance.
Your Realistic Options
Build Internal Capability: Hire dedicated security staff with the right expertise. For most SMEs, this can be challenging due to cost and recruitment difficulties. A qualified security analyst typically costs between £50,000-£80,000 annually, and you need at least two for basic coverage.
Use Managed Security Services: Work with providers who monitor and respond using your Microsoft Defender deployment. You get the expertise and 24/7 coverage without the overhead of building internal capability. This approach works well for many SMEs.
Accept the Risk: Some businesses decide to rely on the automated responses and deal with incidents as they occur. This approach carries risk, as it assumes you'll spot problems quickly enough and have the expertise to respond effectively when needed.
The honest question: can you realistically monitor security alerts around the clock, investigate suspicious activity expertly, and respond to threats rapidly? If the answer is no, you may need additional support.
Making the Right Decision for Your Business
Let's be clear about what you're deciding. You're not choosing whether to use Microsoft Defender - if you're in the Microsoft ecosystem, it's a logical security foundation. The real decision is whether you can manage it effectively yourself or need additional support.
Deploy Microsoft Defender Immediately
If you have Microsoft 365 Business Premium, you've already paid for Defender for Business - use it. Configure the core protections and enable email security features. This gives you solid foundational protection and is significantly better than basic antivirus.
But Don't Stop There
Having Microsoft Defender deployed is not the same as being protected. Ask yourself these questions honestly:
Who watches your security alerts outside business hours? An attack that starts Friday evening has an entire weekend to progress if no-one's monitoring.
Who investigates when threats are detected? Automated containment helps, but someone needs to determine if it's a real incident, understand what's affected, and coordinate the response.
Who keeps your security systems tuned? Out-of-the-box settings provide basic protection, but effective security requires ongoing tuning to catch threats without overwhelming you with false alarms.
Who manages access and investigates suspicious logins? Identity-based attacks are increasingly common. Someone needs to monitor for compromised credentials and unusual access patterns.
Who stays current with evolving threats? The threat landscape changes constantly. Your security needs active management to remain effective.
If you can't answer these questions confidently, managed security services alongside your Microsoft Defender deployment may be worth considering.
What Managed Security Services Provide
TSG's Cyber Care transforms Microsoft Defender from a detection tool into active protection through 24/7 monitoring and expert response. Three service levels scale with your needs and budget:
Monitor: We watch your systems around the clock and alert you to genuine threats via email and portal. Your team maintains control while getting expert threat detection and eliminating false positives.
Respond: Everything in Monitor, plus we investigate and resolve security issues on your behalf during UK working hours. Threats are contained without requiring your team's immediate attention.
Manage: Everything in Respond, plus complete identity management including all joiner/mover/leaver administration. Full security and identity lifecycle management.
All services use Microsoft Sentinel to oversee your Defender deployment, providing sophisticated threat detection and automated response capabilities that can enhance your security investment.
The Bottom Line on Protection
The businesses that survive serious cyber attacks tend to be those that invested in both the right technology and the expertise to manage it effectively before an incident occurred.
Microsoft Defender gives you the detection tools and response capabilities. Managed security services can help ensure those tools are protecting you every hour of every day. You need to build this into your managed IT strategy - endpoint security for small business isn't a single tool that fixes everything.
The difference between being protected and just having security tools often comes down to active, expert management. It's worth making an honest assessment about what you can realistically manage internally, then considering how to address any gaps.
Want to see what properly managed protection looks like? Get in touch and we'll show you the difference between having security tools and being secure.
Frequently Asked Questions
What does Microsoft Defender protect against?
Microsoft Defender provides comprehensive protection against the cyber threats that most commonly affect SMEs: phishing emails, malicious attachments, malware, ransomware, compromised credentials, dangerous websites, and suspicious user behaviour.
The software uses multiple protection layers to catch threats that single-point solutions miss. The depth of protection varies by licensing tier, but even the Business version included with Microsoft 365 Business Premium provides solid, enterprise-grade security.
Is Microsoft Defender good enough?
Microsoft Defender provides solid foundational technology. It uses AI and machine learning to detect sophisticated attacks that traditional antivirus misses. The software capabilities are strong.
However, the question isn't just whether the technology is good enough - it's whether you have the resources to manage it properly. Microsoft Defender detects threats, but someone needs to watch those detections 24/7, investigate them, and respond appropriately. For many SMEs, working with managed security service providers who have the expertise and 24/7 coverage can help ensure the technology provides effective protection.
