The app automatically installs Bing Visual Search and includes code to decrypt cookies saved in other browsers, Rivera said, and it also brings a “free” geolocation web API to the system.
The developer discovered “many” nasty tricks Microsoft integrated in Bing Wallpapers, which include trying to change the browser’s settings and set Edge as the default system browser. If the default browser isn’t Edge, the app will open the default browser after some time asking to enable the previously installed Microsoft Bing Search for Chrome extension.
Why would you download bing wallpaper app anyways? First rule of computers: only install from trusted sources
Most average users consider Microsoft a trusted source, that’s the root cause of a whole lot of crap.