security settingsComputer ConfigurationNot configured

Block Credential Stealing from Windows Local Security Authority Process

Prevents processes from accessing LSASS memory where credentials are stored. Blocks credential theft techniques like Mimikatz.

10 May 20264 min —

Policy path: Computer Configuration > Administrative Templates > Windows Components > Microsoft Defender Antivirus > Microsoft Defender Exploit Guard > Attack Surface Reduction
Supported on: Windows 10, Windows 11, Windows Server 2016 and later

Prevents processes from accessing LSASS memory where credentials are stored. Blocks credential theft techniques like Mimikatz. Security baselines recommend setting it to 1.

Description

Block Credential Stealing from Windows Local Security Authority Process is a Windows Group Policy setting located under Computer Configuration > Administrative Templates > Windows Components > Microsoft Defender Antivirus > Microsoft Defender Exploit Guard > Attack Surface Reduction. It applies to the Computer Configuration branch and is classified as a Critical-level policy in the Attack Surface Reduction (ASR) category.

Prevents processes from accessing LSASS memory where credentials are stored. Blocks credential theft techniques like Mimikatz.

Microsoft sets the default value to 0 while industry security baselines (CIS, NIST, DISA STIG) recommend 1.

Under the hood, this policy is enforced through the Windows registry at HKLM\Software\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\Rules using the value name 9E6C4E1F-7D60-472F-BA1A-A39EF669B4B2. Modifying the value directly through regedit.exe or PowerShell produces the same effect as configuring the GPO, but going through Group Policy is preferred so that the setting is centrally managed and survives reboots, image rebuilds, and policy refresh cycles.

In-depth explanation

This is a critical security control. Misconfiguration creates an exploitable attack path that adversaries actively scan for, and a single overlooked endpoint can compromise the entire fleet. Treat it as a hard baseline requirement rather than an optional tuning knob.

The policy is grouped under Attack Surface Reduction (ASR), which means it is typically applied through a domain-wide GPO linked at the OU level. In a multi-tenant MSP context, scope it through WMI filters or security group filtering rather than linking at the domain root, so that you can roll out progressively (pilot OU → wider rings → all production).

The setting takes effect after the next Group Policy refresh (gpupdate /force for immediate testing, or by default within ~90 minutes for workstations and ~5 minutes on domain controllers). For computer-side policies a reboot may be required; for user-side policies, a sign-off/sign-on cycle is enough.

Use cases

Apply organization-wide hardening of attack surface reduction (asr) on all domain-joined Windows endpoints.
Roll out a CIS Benchmark-aligned baseline targeting 'Block Credential Stealing from Windows Local Security Authority Process' via a dedicated GPO.
Reduce attack surface for accounts that handle privileged credentials or sensitive data.
Standardize the configuration across multiple customer tenants for an MSP-managed fleet.

Security implications

Failing to enforce this policy creates a documented attack path that adversaries actively probe – think Pass-the-Hash, Kerberoasting, NTLM relay, RDP brute-force, LSASS dumping, or token impersonation, depending on the specific control. A single misconfigured endpoint can be enough to pivot to a Domain Admin compromise.

If this policy must remain at default for a legitimate compatibility reason, compensate with a strong detection rule in your EDR/SIEM, isolate the endpoint in its own VLAN, and document the exception with a target remediation date.

How to configure

Open Group Policy Management Console (gpmc.msc) on a domain controller or a workstation with RSAT installed.
Create or edit a GPO linked to the OU containing the target computer configurations. We recommend a dedicated baseline GPO (e.g. SEC – Attack Surface Reduction (ASR)) instead of editing Default Domain Policy.
Navigate to Computer Configuration > Administrative Templates > Windows Components > Microsoft Defender Antivirus > Microsoft Defender Exploit Guard > Attack Surface Reduction.
Open Block Credential Stealing from Windows Local Security Authority Process and set it to 1.
Click OK and close the editor.
On the target endpoint, run gpupdate /force (or wait for the next refresh cycle), then verify with rsop.msc or gpresult /h report.html.

Direct registry path: HKLM\Software\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\Rules\9E6C4E1F-7D60-472F-BA1A-A39EF669B4B2. You can apply the same change with PowerShell:

New-Item -Path 'HKLM\Software\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\Rules' -Force | Out-Null
Set-ItemProperty -Path 'HKLM\Software\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\Rules' -Name '9E6C4E1F-7D60-472F-BA1A-A39EF669B4B2' -Value <value> -Type DWord

Registry mapping

Registry pathHKLM\Software\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\Rules

Value name9E6C4E1F-7D60-472F-BA1A-A39EF669B4B2

Value typeREG_DWORD

Enabled value1

Disabled value0

Frequently asked questions

What does the Block Credential Stealing from Windows Local Security Authority Process Group Policy do?

Prevents processes from accessing LSASS memory where credentials are stored. Blocks credential theft techniques like Mimikatz.

Where do I find this setting in the GPO editor?

Open <code>gpmc.msc</code>, then navigate to <code>Computer Configuration > Administrative Templates > Windows Components > Microsoft Defender Antivirus > Microsoft Defender Exploit Guard > Attack Surface Reduction</code> and look for <strong>Block Credential Stealing from Windows Local Security Authority Process</strong>.

What is the Microsoft default value?

<code>0</code> on a fresh Windows install. Domain-joined machines may inherit a different value if a baseline GPO is already in place.

What value do security baselines recommend?

<code>1</code> – aligned with CIS, NIST, and DISA STIG guidance for current Windows versions.

Can I configure this without a GPO?

Yes, by writing to <code>HKLM\Software\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\Rules\9E6C4E1F-7D60-472F-BA1A-A39EF669B4B2</code> directly via <code>regedit</code>, PowerShell, or Intune. A GPO is preferred for centrally managed environments because it survives reimaging and is easier to audit.