How to enable Google Chrome (chrome.exe) in Microsoft Defender Application Control (MDAC)

To enable Google Chrome (chrome.exe) in Microsoft Defender Application Control (MDAC) when it’s blocked, you need to modify the policies that control application execution. Here’s a step-by-step guide:

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1. Understand the Block

Microsoft Defender Application Control blocks applications based on:

• Code integrity policies.
• Unsigned or untrusted executables.
• Policies that blacklist specific applications.

Ensure the block is not due to a broader organizational policy or misconfiguration.

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2. Open Group Policy Editor

1. Press Win + R, type gpedit.msc, and hit Enter.
2. Navigate to:

   Computer Configuration > Administrative Templates > System > Device Guard > Application Control Policies
   

3. Check if a policy blocking Chrome is configured here.

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3. Identify the Policy Type

Microsoft Defender can block applications based on:

• Allow/Deny Rules in Application Control: Check if Chrome.exe is blacklisted.
• Code Signing: Chrome might not meet the signing or certification requirements.

To identify:

1. Open Event Viewer (eventvwr.msc).
2. Navigate to:

   Applications
   

   If Google Chrome (chrome.exe) is blocked by Microsoft Defender Application Control (MDAC) policies managed through Intune or Microsoft 365 Defender, follow these steps to enable it:

3. 1. Verify the Block in Microsoft 365 Defender

   1. Sign in to the Microsoft 365 Defender portal: https://security.microsoft.com.
   2. Navigate to Reports > Device Control reports to identify the block incident.
   3. Check if Chrome is being blocked due to an Application Control Policy or a Block Rule.

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   2. Update the Application Control Policy in Intune

   1. Sign in to Microsoft Endpoint Manager (Intune):
      • Go to Microsoft Intune admin center.
   2. Locate the Assigned Policy:
      • Navigate to:
        mathematica

        Endpoint security > Application control

      • Find the Application Control policy assigned to the device or user group.
   3. Modify the Policy:
      • Select the policy > Edit.
      • Add Google Chrome (chrome.exe) to the Allowlist (if using Allow policies).
      • If using a hash-based rule, ensure you add Chrome’s hash to the trusted list.
      • If using a path rule, allow the folder where Chrome.exe resides (e.g., C:\Program Files\Google\Chrome).

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   3. Test and Monitor the Policy

   1. Sync the Policy:
      • On the user’s device, open Settings > Accounts > Access work or school.
      • Select the organization account > Sync.
   2. Verify Policy Update:
      • Ensure Chrome.exe is no longer blocked by testing the application.
      • Check logs in Microsoft Defender Security Center or Intune to confirm the block is resolved.

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   4. Adjust Policy in Microsoft 365 Defender (if needed)

   1. Navigate to Device inventory in Microsoft Defender:
      • Go to Settings > Rules > Indicators > Allow/Deny Rules.
   2. Add Chrome.exe or its certificate to the Indicators Allowlist to allow execution across all devices.

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   5. Verify Policy Logs

   1. Open Event Viewer on the affected device.
   2. Navigate to:
      Applications and Services Logs > Microsoft > Windows > CodeIntegrity > Operational

      • Look for errors related to the block (e.g., hash mismatch, path rule).

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   By following these steps, you can unblock Google Chrome through Intune or Microsoft 365 Defender policies. Let me know if you need assistance with any specific step!

4. The Microsoft Defender 365 portal has received updates in 2024 to enhance application control and user management features. If you’re encountering a “chrome.exe is blocked” issue, follow these steps to enable the application using the updated portal interface:
   1. Access Microsoft Defender Portal:
      • Log in to the Microsoft 365 Defender portal using an administrator account.
   2. Locate Application Control Policies:
      • Navigate to the “Endpoint Protection” section under “Assets and Compliance” in the Microsoft Configuration Manager.
   3. Create or Modify Application Control Policy:
      • To create a new policy, select “Create Application Control Policy”, assign it a unique name, and configure the settings to allow trusted applications, such as Chrome.
      • For an existing policy, select it from the list and click “Edit”.
   4. Add Chrome as a Trusted Application:
      • Under the “Inclusions” tab of the policy wizard, add Chrome’s file path (chrome.exe) to the trusted applications list.
      • Ensure the enforcement mode is set to Audit Only initially to test before applying stricter controls.
   5. Deploy Policy:
      • Once configured, deploy the policy to the relevant device collection by selecting the policy and using the Deploy button. You can set evaluation schedules and maintenance window configurations as needed.
   6. Test and Monitor:
      • Restart the affected device(s) to apply the updated policy.
      • Use the DeviceGuardHandler.log file on the device or the Threat Explorer in the Defender portal to verify compliance and identify any issues.
   7. Adjust as Needed:
      • If Chrome still faces issues, check for specific block messages in the Defender event logs or Threat Analytics reports.

   Recent portal updates also include enhanced global search, improved settings unification, and advanced threat hunting capabilities, making it easier to manage these configurations and troubleshoot efficiently.