I'm trying to extract the APK file of an installed Android app WITHOUT root permissions.
I thought that this was impossible, because all APK files for non-system-apps are located in /data/app, and accessing this folder requires root permission. Then I found that there are numerous apps in the Google Play store that seem to have access to the APK files even on non-rooted devices.
Can someone tell me how this is possible? Aren't there backup apps which backup the APK files without root?
Accessing /data/app is possible without root permission; the permissions on that directory are rwxrwx--x. Execute permission on a directory means you can access it, however lack of read permission means you cannot obtain a listing of its contents -- so in order to access it you must know the name of the file that you will be accessing. Android's package manager will tell you the name of the stored apk for a given package.
To do this from the command line, use adb shell pm list packages
to get the list of installed packages and find the desired package.
With the package name, we can get the actual file name and location of the APK using adb shell pm path your-package-name
.
And knowing the full directory, we can finally pull the adb using adb pull full/directory/of/the.apk
Credit to @tarn for pointing out that under Lollipop, the apk path will be /data/app/your-package-name-1/base.apk