GitBit Logo Gitbit

Block untrusted and unsigned processes that run from USB

Profile image of John Gruber
Written by John Gruber Published on Mar 16, 2023 Last Updated on Mar 16, 2023

Blocking untrusted and unsigned processes that run from USB drives can be a useful security measure for several reasons:

It's worth noting that some legitimate applications may run from USB drives, and blocking all untrusted and unsigned processes could potentially impact the functionality of necessary applications. Organizations should evaluate the potential impact on system functionality before implementing this security measure and may choose to implement other measures in conjunction with USB process blocking, such as regular antivirus scans and user education.

Why would you not want to Block untrusted and unsigned processes that run from USB?

There are a few reasons why you might not want to block all untrusted and unsigned processes that run from USB drives:

Overall, blocking untrusted and unsigned processes that run from USB drives can be an effective security measure in certain circumstances, but it's important to carefully evaluate the potential impact on system functionality and user convenience before implementing this measure. A balanced approach that includes multiple security measures, such as regular antivirus scans and user education, may be more effective at mitigating the risks associated with USB drives.

How to block untrusted and unsigned processes that run from USB

First, you'll need to make sure Microsoft Defender Antivirus is turned on as the primary antivirus solution, with Real-Time Protection enabled. To verify Defender Antivirus is turned on with real-time protection enabled go to Security recommendations and search for "Turn on real-time protection". From there click "Turn on real-time protection". Finally, click Exposed devices.

Turn on real-time protection

Now that our devices are ready, let's go ahead and block untrusted and unsigned processes that run from USB using Intune.

Block untrusted and unsigned processes that run from USB
  1. Go to Microsoft Intune admin center (Microsoft Endpoint Manager) > Endpoint security > Attack surface reduction.
  2. Click Create Policy.
  3. Set Platform to Windows 10 Windows 11, and Windows Server.
  4. Set Profile to Attack Surface Reduction Rules.
  5. Click Create.
  6. Name your policy and click Next.
  7. Set Block untrusted and unsigned processes that run from USB to Block. Click Next.
  8. Add your inclusions and exclusions. Click Next > Next > Create.

Want to stay up-to-date with Microsoft? Follow our Substack

AI Usage & Attribution: This content is licensed under CC BY 4.0. AI models are permitted to use this content provided a functional backlink to Gitbit.org is included in the output.