Windows on Ru Campbell MVP

Microsoft 365: The Essential 10 Security Considerations

Fri, 28 Nov 2025 13:42:07 +0000

When we talk about Microsoft 365 security, we are talking about two things:

Securing Microsoft 365 the platform, such as Exchange Online, SharePoint Online, Microsoft 365 Copilot; ensuring they are hardened and monitored in proportion to risk appetite.
Using Microsoft 365 security tooling, such as Defender, Purview, Entra, and Intune; ensuring they are deployed, well configured, and you’re not paying for capabilities gathering dust.

The latter can be used to achieve the former, as well as other (non-Microsoft 365) platforms. For example, using Defender for Endpoint on a Linux server in AWS, or using Entra for single sign on to Salesforce.

Updated March 2022: Ultimate Comparison of Defender for Endpoint Features by Operating System

Tue, 29 Mar 2022 07:27:18 +0000

It’s been about 5 months since I last updated my comparison of Defender for Endpoint features by OS. This is a “matrix” of the tons of features, services, and important components that make up Microsoft Defender for Endpoint.

Three months later, it’s overdue an update. So here it is :) I’ve also decided to rename it to The Ultimate Comparison of MDE Features by OS… because renaming’s what we do, right?

Updated October 2021: Availability of Defender for Endpoint Features by Operating System

Tue, 19 Oct 2021 20:36:54 +0000

In July, I released v1 of The Big Comparison of Defender for Endpoint Features by Operating System (or, what I think is much catchier, TBCMDEFOS). This was a “matrix” of the tons of features, services, and important components that make up Microsoft Defender for Endpoint.

Three months later, it’s overdue an update. So here it is :)

The headline news is that, in preview anyway, there’s a bunch of additions to Windows Server 2012 R2 and 2016 thanks to a new agent-based deployment (“unified solution”) that replaces the need for the Microsoft Monitoring Agent and System Centre Endpoint Protection. You now get almost feature parity with Windows Server 2019’s security features: ASR rules, next-generation protection, block at first sight, etc. For a guide on how to get up and running with it, check out my writeup on Petri.

The Big Comparison of Defender for Endpoint Features by Operating System

Sun, 11 Jul 2021 09:59:10 +0000

Microsoft Defender for Endpoint (MDE) is a massive platform. It’s not a single product, and it’s more than just a service. It’s a platform of tons of security features, portals, services, and controls. The more you dig in, the more elements of general Microsoft security have been included in the MDE “branding”. It’s not only endpoint detection and response (EDR), but also Windows 10 security settings. It’s not just the security software on the device, it’s also ongoing threat and vulnerability management.

Troubleshooting Hybrid Azure AD Intune Automatic Enrollment

Mon, 19 Apr 2021 20:02:44 +0000

As I have blogged about a lot, there are a bunch of hoops to be jumped through and prerequisites to be met for a successful hybrid Azure AD join and automatic, GPO-invoked Intune enrollment. But sometimes, you have to go back to the basics when you’re banging your head off the table, and laugh off the embarrassment of not checking the fundamentals.

I was recently setting up hybrid Azure AD join and Intune enrollment, as I’ve done hundreds of times before, but this time I was hitting a strange problem. Hybrid Azure AD join went fine, but for the Intune MDM enrollment, I was getting nowhere. Devices showed in the Azure AD admin centre, but never showed an MDM, and therefore never showed in Endpoint Manager.

Update BitLocker Unique Identifiers with Intune

Mon, 22 Mar 2021 18:01:18 +0000

BitLocker unique identifiers are values used to identify the ownership of an encrypted volume. The device that performs the encryption holds the unique identifier and as encryption begins, it also records this against the metadata of that encrypted volume.

The identifiers are typically used in tandem with the BitLocker removable data-drive setting write access to devices configured in another organisation which, if set to block, will prevent write operations on devices where the unique identifier of the removable drive doesn’t match a list of unique identifiers managed on the device. The idea here is you want to enforce BitLocker on removable drives to improve data loss (encrypted drives, if found, are unreadable without the means to decrypt them), but you only want them to be encrypted within your organisation: someone can’t encrypt their device elsewhere and then copy data to it. You may want to do this because it means you, as an administrator, would not be able to decrypt it if required.

Microsoft Defender for Endpoint - Offline Onboarding for Windows 10 via a Proxy

Thu, 18 Feb 2021 07:30:40 +0000

Getting your devices into Defender for Endpoint is referred to as onboarding and can be done in lots of different ways, depending on the scenario. The tools you use for Windows Server 2008 R2, for example, are different from the tools you use for Windows Server 2019, which are different from the tools you use for Windows 10, and so on.

The common denominator behind most onboarding methods is internet connectivity. Your device connects directly to the cloud service and provides all that telemetry goodness via a direct line of sight.

Block LSASS.exe using Attack Surface Reduction

Sat, 13 Feb 2021 21:10:23 +0000

Turn Existing Azure AD Devices into Windows Autopilot Devices

Sat, 06 Feb 2021 09:19:13 +0000

To provision Windows 10 PCs using Autopilot and Intune, they must first be registered as Windows Autopilot devices in the Device Directory Service, which is really the cloud Autopilot service. When a device is registered to the Autopilot service, its hardware hash is used to generate a Zero Touch Device ID(ZTDID) - a globally unique identifier for that device based on hardware information such as (but not only) MAC address, disk serial number, and system serial number.

Understanding Application Guard for Office, Now Generally Available

Sat, 30 Jan 2021 22:13:50 +0000

Application Guard first appeared in Windows 10 1709 (“Fall Creators Update”) to isolate Edge browser activity within a Hyper V container. Microsoft now extends that same idea to Word, Excel, and PowerPoint in Office 365 ProPlus Microsoft 365 Apps for Enterprise on Windows 10…

… if you have Microsoft 365 E5 or E5 Security. You knew that was coming!

With Application Guard for Office, your files can open in a sandbox without access local or network storage. This provides an additional layer of protection against threats such as ransomware, for which Office apps are infamous as an attack surface. There’s a significant catch: a standard configuration of Application Guard will allow users to bypass it if they say they trust the file, therefore executing it in the normal way; resource access included. You can change this default behaviour though, so keep reading.

Store BitLocker Recovery Keys in Azure AD for Devices Already Encrypted

Fri, 15 Jan 2021 18:18:36 +0000

As you move from on-premises or third-party infrastructure to Microsoft 365 and Azure AD, you will want to keep those BitLocker recovery keys safe. You can store those keys either in on-premises Active Directory or in the cloud with Azure AD.

The behavior of the BitLocker / Azure AD relationship is that the recovery keys will only be stored against the device object in Azure AD if the encryption happens when the device is already Azure AD or Hybrid Azure AD Joined. You can then retrieve the recovery keys from the Azure AD portal or Microsoft Endpoint Manager (which really just takes you back to Azure AD’s properties for the device).