1 Android malicious apps about privacy leakage 1. Impracticability and hazards of security enhanced Android framework ҉ Many apps,even benign ones, could leak sensitive information without user awareness or consent. ҉ Previous solutions always require to modify the Android or could be easily defeated by malicious apps easily. ҉ IAC：The Android inter-application communication(IAC) is implemented as a message passing system, where messages are encapsulated as Intent objects, which enables reuse of functionality across apps and app components via message passing. ҉ Risk：A malicious app can embed a payload into an IAC message, thereby driving the recipient app into a potentially vulnerable behavior if the message is processed without its fields first being sanitized or validated. 2. Impracticability and hazards of security enhanced Android framework

2 Solutions 1 App Sandbox  1 Qihoo 360 and NCSU proposed AppCage,which can confine the run-time behavior of Android apps without requiring framework modifications or root privilege. AppCage creates a new app to wrap the original one, and leverages two complimentary user-level sandboxes to interpose and regulate an app’s access to sensitive APIs. (AppCage, ASIACCS’15)  2 Saarland University presents the first concept for full-fledged app sandboxing on Android, based on application virtualization and process-based privilege separation to encapsulate untrusted apps in an isolated environment, without firmware modifications, app code modifications or root privileges. (Boxify, USENIX’2015)

Solutions 2 IntentDroid  IBM Security(Isreal)与IBM T. J. Watson Research Center, present the first comprehensive testing algorithm for Android IAC, and describe a catalog, stemming from our field experience, of 8 concrete vulnerability types that can potentially arise due to unsafe handling of incoming IAC messages.They have realized their testing approach as the IntentDroid system, available as a commercial cloud service.  IntentDroid utilizes lightweight platform-level instrumentation, implemented via debug breakpoints (to run atop any Android device without any setup or customization), to recover IAC-relevant app- level behaviors. (IntentDroid, ISSTA’2015) Scanning results