Extensions installation must be blacklisted by default.
Extensions are developed by third party sources and are designed to extend Google Chrome's functionality. An extension can be made by anyone, to do and access almost anything on a system; this means they pose a high risk to any system that would allow all extensions to be installed by default. Allows you to specify which extensions the users can NOT install. Extensions already installed will be removed if blacklisted. A blacklist value of '*' means all extensions are blacklisted unless they are explicitly listed in the whitelist. If this policy is left not set the user can install any extension in Google Chrome.
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\Extensions\ Policy Name: Configure extension installation blacklist Policy State: Enabled Policy Value: *
Universal method: 1. In the omnibox (address bar) type chrome://policy 2. If ExtensionInstallBlacklist is not displayed under the Policy Name column or it is not set to * under the Policy Value column, then this is a finding. Windows method: 1. Start regedit 2. Navigate to HKLM\Software\Policies\Google\Chrome\ExtensionInstallBlacklist 3. If the a registry value name of 1 does not exist under that key or its value is not set to *, then this is a finding.