Google Cast must be disabled.

If this policy is set to ”True” or is not set, Google Cast will be enabled, and users will be able to launch it from the app menu, page context menus, media controls on Cast-enabled websites, and (if shown) the “Cast toolbar” icon. If this policy set to ”False”, Google Cast will be disabled.

Universal method: 1. In the omnibox (address bar) type chrome://policy 2. If "EnableMediaRouter" is not displayed under the "Policy Name" column or it is not set to "False", this is a finding. Windows method: 1. Start regedit 2. Navigate to HKLM\Software\Policies\Google\Chrome\ 3. If the "EnableMediaRouter" value name does not exist or its value data is not set to "0", this is a finding.

Windows group policy: 1. Open the “group policy editor” tool with gpedit.msc 2. Navigate to Policy Path: Computer Configuration\Administrative Templates\Google\Google Chrome\Google Cast Policy Name: Enable Google Cast Policy State: Disabled Policy Value: N/A