‘Apps on Windows Phone and RT are unencrypted’
A developer who works with Windows Phone 8.1 complains that apps on the mobile operating system are stored unencrypted. This makes sideloading possible via a small detour. This would make it easy to copy paid apps as well.
On Reddit, a developer using the pseudonym Snickler complains that the appx packages on Windows Phone 8.1, as well as Windows RT, can be easily found via the Bing search option. With the help of software, the unencrypted appx packages can be extracted and the components recompiled so that they can be reinstalled via sideloading on, for example, another device.
According to Snickler, Microsoft should fix this problem because it makes it possible to distribute purchased apps via sideloading. He says he has received little feedback so far after a posting on the XDA forum.
It is not yet clear whether Microsoft will fix this problem. He also reports that developers who want to prevent Windows Phone 8.1 apps from being copied should develop them in Silverlight. These packages are still encrypted.