How useful are existing monitoring languages for securing Android apps?

Abstract: The Android operating system is currently dominating the mobile device market in terms of penetration and growth rate. An important contributor to its suc-cess are a wealth of cheap and easy-to-install mobile applications, known as apps. Today, installing untrusted apps is the norm, though this comes with risks: malware is ubiquitous and can easily leak confidential and sensitive data. In this work, we investigate the extent to which we can specify complex infor-mation flow properties using existing specification languages for runtime monitoring, with the goal to encapsulate potentially harmful apps and prevent private data from leaking. By modelling a set of representative, Android-specific security policies with Tracematches, JavaMOP, Dataflow Pointcuts and PQL, we are able to identify policy-language features that are crucial for effectively defining runtime-enforceable Android security properties. Our evaluation demonstrates that while certain property languages suit our pur-poses better than others, they all lack essential features that would, if present, allow users to provide effective security guarantees about apps. We discuss those shortcom-ings and propose several possible mechanisms to overcome them.