Windows Endpoint Hardening with Microsoft Intune: A Practical Security Baseline

"Harden the endpoints" is the kind of instruction that sounds like a single task and is actually nine separate configuration surfaces, each with its own blade in Intune, its own gotchas, and its own way of quietly breaking something if you enable it wrong. This is the practical version: what each control actually stops, where to configure it, and the order that gets you a genuinely hardened fleet without generating a helpdesk queue on day one.

Configuration alone was never the whole story, compliance is a checklist, not a security guarantee, but a checklist that includes the right nine items is a very different starting point from one that doesn't.

The Nine Controls, At a Glance

1. Security Baselines: Start Here, Not Last

A Security Baseline in Intune is a pre-configured group of hundreds of individual settings, based on Microsoft's own recommended configuration for a given Windows version, that you deploy as a single profile instead of hand-picking every value yourself.

2. Password Policy and Windows Hello for Business

The single biggest shift in password guidance over the last several years: length and MFA beat complexity and rotation. Forcing a password change every 60 days trains users to increment a number at the end of the same password, it doesn't produce meaningfully stronger security.

Configure this through Endpoint Security → Account Protection, where Windows Hello for Business policy lives alongside the older password-complexity CSPs. If a device has WHfB configured, the user signs in with a PIN backed by the device's TPM, or biometrics, and the actual password is used dramatically less often, which is exactly the point: a stolen password does nothing on its own if MFA and modern authentication are already doing the real work.

3. Microsoft Defender Antivirus

Defender is the patrol guard in the security team analogy, watching live behaviour rather than checking configuration or identity. The baseline settings that matter most, configured under Endpoint Security → Antivirus:

4. Windows Firewall

Intune manages Windows Firewall through Endpoint Security → Firewall, with separate profiles for the three network location types Windows itself recognises: Domain, Private, and Public.

5. BitLocker

BitLocker makes the data on a disk unreadable without the recovery key the moment that disk is physically separated from a working Windows sign-in, lost laptop, stolen drive, decommissioned hardware sold without wiping it properly.

Configure this under Endpoint Security → Disk encryption. The setting worth double-checking before wide deployment is recovery key escrow: a device that encrypts successfully but whose recovery key never made it to Entra ID or AD is a device that's one BIOS update or hardware change away from being permanently locked, with no way back in for anyone, including you.

6. Credential Guard

Credential Guard uses virtualization-based security (VBS) to isolate the process that stores authentication secrets, LSASS, in a separate, hardware-protected memory space that the main operating system, and anything running on it including malware with admin rights, cannot directly access.

What it actually stops: the class of attack where malware dumps LSASS memory to extract cached password hashes or Kerberos tickets, then reuses those credentials to move to other machines, pass-the-hash and pass-the-ticket, both extremely common in real ransomware and lateral-movement toolkits.

Configure it through Endpoint Security → Account Protection, alongside Windows Hello for Business. Some older applications and certain legacy authentication methods that rely on directly accessing credential material in memory can break once Credential Guard is active, which is exactly why this is a pilot-first rollout, not a tenant-wide flip.

7. SmartScreen

SmartScreen is a reputation check that runs before a downloaded file executes or a site loads, checking it against Microsoft's cloud database of known-good and known-bad applications and sites.

Set both Check apps and files and SmartScreen for Microsoft Edge to Block, not just Warn. Warn mode gives users a dismissible prompt they'll click through under time pressure; Block actually stops the file from running until an admin makes an exception.

8. Attack Surface Reduction (ASR) Rules

ASR rules don't scan for known malware signatures, they block specific behaviours that legitimate software almost never needs and malware relies on constantly: an Office document spawning a child process, a script pulling content from the internet and executing it directly, a process trying to read credentials out of LSASS memory.

Some of the highest-value rules to start with, all configured under Endpoint Security → Attack surface reduction:

9. Local Administrator Controls

The last control is about a different kind of risk entirely: what happens once someone, or something, already has code running on the device. If that code is running as local administrator, it can disable other protections, install anything, and move laterally far more easily than if it's running as a standard user.

Two Intune features work together here, and the full walkthrough for setting either one up is in the licensing guide:

Putting the Baseline Together

Summary Table

None of these nine controls is optional in a genuinely hardened fleet, and none of them is safe to enable tenant-wide on day one. The pattern that runs through every single one, baseline first, pilot before enforce, audit before block, is the same discipline Conditional Access rollouts depend on, because it's the same underlying risk: a security control strong enough to matter is also strong enough to cause an outage if you skip the pilot step.

Which of these nine is still sitting on Microsoft's default rather than a deliberately reviewed value in your tenant? Attack Surface Reduction rules are the ones I see left in Audit mode the longest, often because nobody circled back to review the logs. Drop a comment with what's still pending in yours.