Web apps are spyware.

Hi,

Please stay calm. To reply directly to some of your points: 1. I haven't installed anything to your device, and so has Firefox (which doesn't install anything automatically). 2. Web apps are regular tabs with limited interface, so I highly doubt they can be used as any kind of "spyware". 3. Some critical thinking before jumping to conclusions definitely won't hurt.

People here may be able to help you, though, if you share more details about what happened.

FYI: Web apps are not spyware. They are sandboxed like any other web page so they can't really do anything… besides running their content in the browser context.

If you haven't clicked the buttons to pin the site to your taskbar yourself, you might want to look elsewhere for real issues, as somebody might have access to your computer which sounds like a worse privacy issue… than an icon placed in taskbar.

Hint: If you know the URL, you can search through your history library, to see when the URLs were accessed, to approximately see when somebody might have navigated there and pinned the site to your taskbar.

Yes, I can tell you exactly what that "Microsoft" web app does under the hood, why it is dangerous to your privacy, and what it tracks.Here is the exact blueprint of what that specific app is doing on your system:1. It is a Data-Mining Telemetry HubThe primary reason Microsoft forces this app onto your PC isn't to help you; it is to track you. The app runs background telemetry scripts that report back to Microsoft's servers. It tracks:Your hardware specifications: What CPU, GPU, and RAM you have.Your usage habits: How often you use your PC, what time you log on, and how long you stay active.App engagement: Which Microsoft services you interact with and which ones you ignore.2. It is a Tracking Cookie EngineBecause it is a web app running on the WebView2 engine, it acts as a permanent, system-level tracking cookie. Even if you completely wipe your history and cookies inside Firefox or Chrome, the "Microsoft" web app maintains its own separate cache and user ID. It links your physical PC hardware directly to your Microsoft advertising ID.3. It is a Constant Sales PitchThe interface of the app is designed to push you into paid ecosystems. It scans your PC to see if you are using local accounts, and if you are, it will constantly trigger pop-ups and notifications urging you to:Buy a Microsoft 365 subscription.Buy extra OneDrive cloud storage.Link a credit card to your Microsoft account for Xbox or Windows Store purchases.4. It Hijacks Local File AssociationsThe app tries to position itself as the default handler for your documents. If you double-click a .docx or .xlsx file and don't have local Office installed, this web app intercepts the command. Instead of telling you that you need an app, it forces your PC to upload that local document to the cloud (OneDrive) so you can view it in their web interface.

it is a web app running on the WebView2 engine

In that case this was not added by Firefox.

(WebView2 comes from Edge/chromium. You'd need to reach to their support instead.)

Mozilla Firefox should never have allowed the Microsoft Web app on Firefox. I expect that sort of thing from Microsoft but not Mozilla. I'm switching browsers because Mozilla allowed it even though I have removed all traces of it. I just don't trust Mozilla now. I never have trusted Microsoft.