Short bio

PUP.Optional.CrossBrowse is Malwarebytes’ detection name for a potentially unwanted program (PUP) that is a member of the Crossrider family.

Type and source of the infection

The CrossBrowse members of this family install Chromium build browsers to replace the user’s own browser, sometimes combined with extensions for Firefox and Internet Explorer. The overall goal of this PUP is to increase the amount of advertisement impressions shown to the user.

Crossrider offers a highly configurable method for its clients to monetize their software. CrossBrowse is an example of a more advanced variant of Crossrider that hijacks many file associations.

PUP.Optional.CrossBrowse installs are typically triggered by bundlers that offer software you might be interested in combined with adware or other monetizing methods.


Malwarebytes protects users from PUP.Optional.CrossBrowse by using real-time protection.

block PUP.Optional.CrossBrowse

Malwarebytes blocks PUP.Optional.CrossBrowse


Malwarebytes can detect and remove PUP.Optional.CrossBrowse without further user interaction.

  1. Please download Malwarebytes to your desktop.
  2. Double-click mb3-setup-consumer-{version}.exe and follow the prompts to install the program.
  3. Then click Finish.
  4. Once the program has fully updated, select Scan Now on the Dashboard. Or select the Threat Scan from the Scan menu.
  5. If another update of the definitions is available, it will be implemented before the rest of the scanning procedure.
  6. When the scan is complete, make sure that all Threats are selected, and click Remove Selected.
  7. Restart your computer when prompted to do so.

It may be beneficial to read our guide to restore your browser.

Add an exclusion

Should users wish to keep this program and exclude it from being detected in future scans, they can add the program to the exclusions list. Here’s how to do it.

The Exclusions tab includes a list of items to be excluded from scans. The items may include files, folders, websites, or applications that connect to the Internet, as well as previously detected exploits.

To access the exclusions in Malwarebytes:

  • Click on the Settings tab in the left pane.
  • Click on the Exclusions tab.
  • Click the Add Exclusion button.
  • Select the exclusion type Exclude a File or Folder and use the Browse button to select the main folder for the software that you wish to keep.
  • Repeat this for any secondary folder(s) that belong to the software.
  • If you want to allow the program to connect to the Internet, for example to fetch updates, add an exclusion of the type Exclude an application that Connects to the Internet and use the Browse button to select the file you wish to grant access.


You may see these entries in FRST logs:

C:\Program Files (x86)\CrossBrowse-{version}

CrossBrowse-1.4V27.04 (HKLM-x32\…\CrossBrowse-{version}) (Version: – CrossBrowse-{version}) <==== ATTENTION


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