Microsoft Defender has evolved significantly over the last few years. What was once primarily associated with antivirus and endpoint protection has become a much broader security platform, spanning devices, identities, email, applications, cloud services and security operations.

However, there is a big difference between owning Microsoft Defender and making full use of Microsoft Defender. Many organisations have invested in Microsoft security licensing and successfully deployed products such as Microsoft Defender for Endpoint, Defender for Office 365 and Defender for Identity, but that doesn't necessarily mean every available security capability has been configured or enabled.

In fact, some of the most valuable Defender functionality can remain unused simply because it wasn't part of the original deployment, administrators were concerned about its impact on users, or nobody has revisited the configuration as Microsoft's security platform has evolved.

So, if your organisation already uses Microsoft Defender, here are ten capabilities we think are worth investigating.

1. Automatic Attack Disruption

One of the most interesting developments within Microsoft Defender XDR is Automatic Attack Disruption. Traditionally, security technology detects suspicious activity, creates an alert and relies on a security analyst or IT administrator to investigate and respond. The obvious problem is that sophisticated cyber attacks can move extremely quickly, particularly once an attacker has compromised an identity or established access to a device.

Automatic Attack Disruption is designed to help close that gap. Microsoft Defender XDR can correlate high-confidence signals across the Microsoft security ecosystem to understand when a genuine attack is taking place and take action to disrupt it. Depending on the attack and the Defender products deployed, this can include containing compromised devices or identities and restricting an attacker's ability to continue moving through the environment.

For organisations worried about ransomware, identity compromise and lateral movement, this ability to move from simply detecting an attack to disrupting it while it is happening can be extremely valuable.

2. Automated Investigation and Remediation

Security teams can face hundreds or even thousands of alerts, and investigating every one manually isn't always realistic. Microsoft's Automated Investigation and Remediation, often referred to as AIR, can help automate parts of this workload by investigating suspicious activity and, depending on how the environment has been configured, taking or recommending remediation actions.

The objective isn't to remove humans from security operations. Instead, automation can deal with repetitive investigation tasks and speed up the initial response, allowing internal IT teams or security analysts to concentrate on incidents that require their expertise and judgement.

For organisations already using Defender for Endpoint, it is worth reviewing how automation has been configured, including automation levels, device groups and remediation processes. Simply having the capability available doesn't necessarily mean you're getting the benefit from it.

3. Attack Surface Reduction Rules

Microsoft Defender for Endpoint includes Attack Surface Reduction rules, commonly known as ASR rules. These are designed to restrict behaviours frequently exploited by attackers, including potentially dangerous activities involving Microsoft Office applications, scripts, executable content and credential theft.

ASR rules are particularly interesting because they can potentially stop malicious behaviour before traditional endpoint protection even needs to detect malware. However, organisations can sometimes be cautious about deploying them because poorly planned policies have the potential to interfere with legitimate applications or business processes.

Rather than leaving them disabled, organisations can take a staged approach. Rules can be assessed and tested before being introduced more widely, allowing IT teams to identify compatibility issues while gradually strengthening endpoint protection. If your Defender environment has been running for several years, reviewing your ASR configuration should be high on the list.

4. Microsoft Defender for Identity

Modern cyber attacks increasingly focus on identities rather than individual devices. If an attacker compromises a legitimate user's credentials, their activity can potentially look very different from a traditional malware infection.

Microsoft Defender for Identity provides additional visibility into identity-related threats and suspicious activity, allowing security teams to investigate identity signals alongside endpoint, email and cloud security information. This becomes particularly powerful when combined with the wider Microsoft Defender XDR environment.

An attack might start with phishing, progress to compromised credentials and then involve unusual activity across devices and applications. Looking at those individual alerts separately can make the attack difficult to understand. Connecting identity security with the rest of the Defender ecosystem provides much greater context around what is actually happening.

5. Defender for Cloud Apps and Shadow IT Discovery

Most organisations know which cloud applications they officially support, but that doesn't necessarily mean they know which applications employees are actually using. Staff can adopt new SaaS platforms simply by opening a browser and creating an account, often without involving IT at all.

Microsoft Defender for Cloud Apps can help organisations discover and understand cloud application usage, providing greater visibility over Shadow IT. This is becoming even more important with the rapid adoption of generative AI services, where employees may experiment with new tools and potentially upload corporate information without understanding how that information will be stored or processed.

Discovery doesn't automatically mean blocking everything. Instead, it gives security and IT teams the information they need to make informed decisions about which applications should be sanctioned, monitored, restricted or blocked. Without that visibility, organisations can find themselves trying to govern an environment they cannot actually see.

6. Advanced Hunting

Microsoft Defender generates a significant amount of security telemetry across endpoints, identities, email and cloud applications. Advanced Hunting allows security analysts to actively investigate this information rather than simply waiting for Defender to generate an alert.

For example, a security team investigating a suspicious incident might want to establish whether a particular file has appeared on other devices, which users received a suspicious email, whether endpoints communicated with a malicious domain, or whether unusual authentication activity occurred around the same time.

This proactive approach can be extremely useful for organisations developing more mature security operations. Instead of Defender simply telling you that something suspicious has happened, Advanced Hunting gives experienced security teams the ability to explore the underlying information and determine whether related activity exists elsewhere across the environment.

7. Email Authentication and Anti-Phishing Protection

Email remains one of the most common starting points for cyber attacks, which makes the configuration of Microsoft Defender for Office 365 particularly important. Organisations should regularly review policies covering phishing protection, impersonation protection, Safe Links and Safe Attachments rather than assuming the configuration created several years ago still represents best practice.

This review should also extend beyond Defender itself to the wider email security configuration, including SPF, DKIM and DMARC. Together, these technologies can help reduce the effectiveness of domain spoofing and email impersonation attacks.

The important point is that email security isn't something organisations should configure once and forget. Attack techniques continue to change, Microsoft continues to develop new protections, and the policies that were appropriate when a Microsoft 365 tenant was originally deployed may no longer provide the level of protection the organisation expects.

8. Device Discovery

Most businesses have a reasonably good idea of how many laptops, desktops and servers they manage. The question is whether that matches the number of devices that actually exist across the corporate network.

Device Discovery within Microsoft Defender for Endpoint can help identify devices that haven't necessarily been onboarded into Defender. This can expose unmanaged endpoints and other network-connected equipment that might otherwise be missing from the organisation's security picture.

Printers, network appliances, mobile devices, IoT equipment, legacy machines and forgotten systems can all introduce additional exposure. From a security perspective, you cannot properly protect an asset you don't know exists. Device discovery therefore provides an important opportunity to compare the organisation's documented IT estate with what is actually visible across its networks.

9. Microsoft Defender Vulnerability Management

Identifying vulnerabilities is relatively straightforward. Deciding which vulnerabilities genuinely represent the greatest risk to your organisation is considerably harder.

Microsoft Defender Vulnerability Management can help organisations understand vulnerabilities, software weaknesses, security recommendations and exposure across their endpoint estate. Rather than treating every vulnerability equally, security and IT teams can use this information to make more informed decisions about where remediation activity should be prioritised.

This creates a much more useful conversation between security and IT operations. Instead of simply asking, "How many vulnerabilities do we have?", organisations can start asking, "Which vulnerabilities create the greatest exposure, and what should we fix first?"

That distinction becomes increasingly important when IT teams have limited resources and potentially thousands of vulnerabilities or recommendations competing for attention.

10. Bringing Everything Together with Microsoft Defender XDR

Perhaps one of the biggest opportunities isn't an individual Defender feature at all. It's using the Microsoft Defender XDR platform to bring signals from multiple areas of the organisation together.

Cyber attacks rarely stay within neat technology boundaries. An attack might begin with a phishing email, lead to a user's credentials being compromised, involve suspicious identity activity and ultimately progress to endpoints or cloud applications. If these activities are viewed as separate alerts within separate tools, understanding the complete attack can become difficult.

Microsoft Defender XDR is designed to correlate those signals and provide security teams with a broader view of an incident. That context can help analysts understand how an attack started, which identities and devices were involved, how far it progressed and what needs to happen next.

For organisations that already have multiple Microsoft security products deployed, making sure those technologies are properly integrated can be just as important as deploying another security tool.

Having Microsoft Defender Isn't the Same as Optimising It

Microsoft continues to invest heavily in its security ecosystem, and that creates a significant opportunity for organisations already standardising on Microsoft 365, Azure and Microsoft security technologies. The challenge is that purchasing licences or deploying Defender doesn't automatically create a mature security environment.

Policies need to be configured correctly, devices need to be onboarded, identities need to be protected, email security needs to be continually reviewed and automation needs to be appropriate for the organisation. Just as importantly, the entire configuration needs to be reassessed as Microsoft's technology and the wider threat landscape change.

That means there is a very simple question worth asking:

Are you getting all the security capability you're already paying for?

At HybrIT, we help organisations assess, configure and optimise their Microsoft security environments across Microsoft Defender, Microsoft Entra, Microsoft Purview, Microsoft Sentinel and the wider Microsoft 365 ecosystem.

Whether you already have Microsoft Defender deployed or you're reviewing your wider Microsoft security strategy, we can help identify configuration gaps, unused capabilities and practical opportunities to strengthen protection across your users, identities, devices, email and cloud services.

Are you getting everything you can from Microsoft Defender?

If you're not sure which Microsoft Defender capabilities are enabled, correctly configured or actively protecting your organisation, HybrIT can help.

Our Microsoft security specialists can review your existing environment, highlight gaps and help you get more value from the Microsoft security technology you're already investing in.

Speak to HybrIT today about reviewing and strengthening your Microsoft security environment.