Android run-time permission exploitation user awareness by means of formal methods

Our mobile devices store a lot of sensitive and critical information. Moreover, considering the ability of smartphones and tables to detect the position and to record audio, it is not absolutely an exaggeration to admit that potentially our devices can easily spy on us. The ability to perform these crucial tasks must be granted by the user at the time of their first use by accepting the so-called permissions. The problem is that in Android, once these permissions are granted, the application can always use them without notifying the user. In this paper, we propose a methodology, based on formal methods, aimed to detect the exact point in the code (in term of package, class and method) of an Android application where a permission is invoked at run-time. Moreover we design a tool able to advise the user whether a permission is invoked, in this way the user can be informed about the application behaviour.