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Short bio

PUM.Optional is a category of Malwarebytes’ detections that deal with potentially unwanted modifications (PUMs). These potentially unwanted modifications are usually found in the Windows registry or in a browsers’ settings.

Type and source of infection

Typically, PUMs are registry settings or browser modifications that could have been changed by PUPs or malware. You can find which settings have been changed and where by looking up the PUM detection profile.


PUM.Optional is a detection category only, so there is no protection against PUMs. But we do offer protection against the PUPs and malware that are known to make these modifications.


Malwarebytes can detect and remove PUMs without further user interaction.

  1. Please download Malwarebytes to your desktop.
  2. Double-click MBSetup.exe and follow the prompts to install the program.
  3. When your Malwarebytes for Windows installation completes, the program opens to the Welcome to Malwarebytes screen.
  4. Click on the Get started button.
  5. Click Scan to start a Threat Scan.
  6. Click Quarantine to remove the found threats.
  7. Reboot the system if prompted to complete the removal process.

Add an exclusion

When a Potentially Unwanted Modification (PUM) is detected on your computer, Malwarebytes for Windows does not know whether it was authorized. Optimization software, malware, and Potentially Unwanted Programs (PUPs) are known to make these types of changes, hence they are regarded as potentially unwanted by design. To have Malwarebytes for Windows ignore a PUM, you must add the PUM to the Allow list. Here’s how to do it.

  1. When a PUM appears in the list of Scan results.
  2. Uncheck the entry or entries related to the PUM.
  3. Then click on Next.
  4. You will see a prompt giving you several options.
  5. Choosing Always ignore will add the PUM to the Allow List.
  6. You can remove them there when you decide they should no longer be ignored.
  7. When the PUM is on the Allow list it will no longer show up in your Scan results.