Augmenting the android app permission system using dynamic analysis Android’s app ecosystem relies heavily on third-party libraries as they facilitate code development and provide a steady stream of revenue for developers. However, while Android has moved towards a more fine-grained runtime permission system, users currently lack the required resources for deciding whether a specific permission request is actually intended for the app itself or is requested by possibly dangerous third-party libraries. In this paper we present Reaper, a novel dynamic analysis system that traces the permissions requested by apps in real time and distinguishes those requested by the app’s core functionality from those requested by third-party libraries linked with the app. Our study on over 5K popular apps demonstrates the large ...