Managing endpoint security is a critical aspect of any organization’s IT strategy. As data breaches become increasingly common, controlling access to data transfer methods like USB drives is essential. Microsoft Intune allows administrators to enforce such restrictions centrally, ensuring a consistent policy across the organization. Blocking USB drives using Microsoft Intune is one of the most effective ways to prevent unauthorized data exfiltration or malware infections.

TL;DR

If you’re looking to block USB drives across your organization using Microsoft Intune, you can do so through configuration profiles, specifically by using settings in Endpoint Security or Administrative Templates. This helps reduce the risk of data loss and external threats. The process involves creating a policy and assigning it to the appropriate user or device groups. Testing and verifying the policy are crucial to ensure the restriction is functioning as intended.

Why Block USB Drives?

USB drives, while convenient, can pose multiple security risks if left unmanaged:

• Data leakage: Company data could be copied to an unsecure device without authorization.
• Malware threats: USB drives are often used as vehicles for spreading malware.
• Loss or theft: USB drives are small and can be easily lost or stolen, putting sensitive data at risk.

To mitigate these risks, organizations increasingly turn to centralized management tools like Microsoft Intune to enforce USB usage policies without depending on manual configurations.

Requirements Before You Start

Before you configure policies to block USB drives using Microsoft Intune, ensure the following prerequisites are met:

• Microsoft Intune is properly set up and integrated with your organization’s Azure Active Directory.
• Devices are enrolled in Intune and are running supported Windows editions (typically Windows 10 or later).
• You have appropriate administrative roles to create and assign compliance or configuration policies in Intune.

Methods to Block USB Drives

There are multiple ways to block USB drives via Intune depending on the required level of control and customization. The two most recommended approaches include:

1. Using Endpoint Security Policies
2. Using Configuration Profiles with Administrative Templates

Method 1: Block USB Drives via Endpoint Security Policies

This is a streamlined way to enforce settings related to device control, specifically removable storage.

1. Sign in to the Microsoft Intune Admin Center.
2. Navigate to Endpoint Security > Attack surface reduction.
3. Click + Create Policy.
4. Select the platform as Windows 10 and later.
5. Choose Removable Storage Access Control for the profile type.
6. Click Create.
7. In the configuration settings, enable the option Deny write access to removable drives not protected by BitLocker or further restrict by setting Deny all access.
8. Assign the policy to appropriate security groups (user or device-based).
9. Review and create the policy.

After deployment, the devices within the defined scope will automatically apply the restriction upon compliance check-in.

Method 2: Block USB Drives via Configuration Profiles (Administrative Templates)

This method gives you more granular control over device settings by leveraging group policy settings available in Windows through Intune.

1. Open the Intune Admin Center.
2. Go to Devices > Configuration Profiles.
3. Click + Create Profile.
4. Choose the platform as Windows 10 and later and profile type as Templates > Administrative Templates.
5. Name the policy and proceed to Configuration settings.
6. In the settings search box, type “removable storage” or “USB”.
7. Enable the policy named All Removable Storage classes: Deny all access.
8. Click OK, assign the policy to the required groups, and finish creation.

This profile completely denies access to all removable storage devices by default.

Testing the Policy

It’s critical to test your policy on a limited scope before a full-scale rollout. Assign the policy to a small group of test devices or users and verify:

• USB drives prompt an access denied message when connected.
• No read or write operations can be performed on the drive.
• Policy settings are present in the local system by running gpresult /r or reviewing the registry editor.

This step helps ensure that the configuration behaves as expected without disrupting authorized workflows.

Handling Exceptions

You might have scenarios where certain teams require the use of USB drives. Instead of applying the policy universally, create exception policies:

• Exclude specific groups during assignment configuration.
• Use Compliance Policies that allow conditional access based on encryption or device posture.
• Set audit logs and track file access for controlled usage of USB devices.

Monitoring and Troubleshooting

Once deployed, Intune offers capabilities to monitor the status of devices under policy:

• Navigate to Devices > Monitor > Assignment Status to check if the policy is successfully applied.
• Review Endpoint Security > Reports to track compliance.
• Check Event Viewer logs on the client machine for any errors during USB access attempts.

Ensure that devices are regularly syncing with Intune by having a consistent internet connection and verifying that the Intune Management Extension is installed and active.

Best Practices

To maintain high security standards while using Intune to block USB access, consider the following practices:

• Document your policy scope and exceptions for audit and troubleshooting purposes.
• Communicate changes to staff to minimize support requests and frustration.
• Review policies quarterly to ensure they align with evolving business needs.
• Integrate alerts into your SIEM or Microsoft Defender dashboards for real-time response to breaches or unauthorized usage.

Conclusion

Blocking USB drives using Microsoft Intune is a powerful way to enforce security policies across an enterprise. By choosing between Endpoint Security or Configuration Profiles with Administrative Templates, administrators can tailor USB access restrictions according to organizational needs. When implemented correctly, this policy significantly reduces the risk of data loss, unauthorized data transfers, and malware spread via removable devices.

Frequently Asked Questions (FAQ)

• Can I allow only encrypted USB drives?
  Yes, using the Endpoint Security policy, you can allow only BitLocker-encrypted drives while blocking others under the “Deny write access to removable drives not protected by BitLocker” setting.
• Will this affect USB keyboards or mice?
  No, the policy targets storage-class devices. Input devices like USB keyboards and mice will continue to function normally.
• Can end-users bypass the restriction?
  No, once applied through Intune and protected with admin privileges, users without elevated rights cannot override or modify the policy.
• How often do devices check for policy updates?
  Devices typically sync with Intune at regular intervals (every 8 hours by default), or immediately upon reboot or manual sync.
• Is there a way to log USB activities even if drives aren’t blocked?
  Yes. You can implement auditing through Event Viewer or use Microsoft Defender for Endpoint to track USB activity without outright blocks.