Beware of malware from Microsoft

Microsoft released the official Bing Wallpaper app on the Microsoft Store this week. The app was previously only available as a standalone download.

It is a basic application that changes the wallpaper of the Windows desktop by providing a new image every day as well as information about each image for users.

The store app is actually, it's a Win32 application.

But it turns out that this particular app has a darker side.
Its behavior resembles that of malware

Software engineer Rafael Rivera, known for apps like EarTrumpet, installed the Bing Wallpaper app and analyzed its behavior. He published his findings in X.

Below are his key findings:

• The app automatically installs Bing Visual Search on your Windows 10 or 11 system.
• It displays a prompt on first run that includes an option to make Microsoft Bing the default homepage and search engine in Edge, Firefox, and Chrome.
• Includes code to "consult and decrypt" Edge, Chrome and Firefox cookies.
• It has access to the geolocation web API.
• It suggests making Microsoft Edge the default browser.
• Launches a tab in your default browser (not Edge) that recommends enabling the Microsoft Bing search extension for that browser.

Everything the researcher claims is accurate. Rivera suggests avoiding the app at all costs, which of course we do.

It's sad to see Microsoft implement behaviors in some of its apps that are generally only found in malware apps.

Microsoft Defender would probably show Bing Wallpaper as a PUP (potentially unwanted program) if it wasn't from Microsoft.