ActivityShielder: An Activity Hijacking Defense Scheme for Android Devices

With the growing popularity of smartphones in vast areas, the security of Android has been a vital pursuit for developers. Among the security issues in Android, Activity hijacking attacks pose severe threat to normal APPs and sensitive input data by exploiting flaws in Android UI management mechanism with high elusiveness and extensive harmfulness. However, to our best knowledge, existing defenses either only work under particular scenarios or incur obvious false positives. To make up for this vacancy, we propose a novel Activity hijacking defense scheme named "ActivityShielder" for Android tasks. The scheme is designed to manage the entities of UI and it can detect and block multiple Activity hijacking attacks explicitly. We have developed a fully functioning prototype of ActivityShielder, and our evaluation results show that ActivityShielder (1) can effectively resist activity hijacking attacks and avoid existing false positives in multi-version Android systems; with (2) a minor performance impact (lower than 2%) to the system.