Windows Defender Chrome and Firefox extensions are currently under testing by Microsoft but will only cautiously open untrusted sites in the Edge browser..
Microsoft Releases Windows Defender Extensions for Chrome and Firefox
The security tool, previously only available to the Edge browser, helps keep PCs safe by opening pages not listed in a user’s trusted sites log in a virtual container.
Although the extensions are readily available to rival Microsoft browsers, it won’t entirely work within Chrome or Firefox. Instead, if it detects an untrusted site, it will open Edge in an isolated session.
Here’s how Microsoft explains the process in a blog post:
“When users navigate to a site, the extension checks the URL against a list of trusted sites defined by enterprise administrators. If the site is determined to be untrusted, the user is redirected to an isolated Microsoft Edge session. In the isolated Microsoft Edge session, the user can freely navigate to any site that has not been explicitly defined as trusted by their organization without any risk to the rest of system. With our upcoming dynamic switching capability, if the user tries to go to a trusted site while in an isolated Microsoft Edge session, the user is taken back to the default browser.”