IntelliDroid: A Targeted Input Generator for the Dynamic Analysis of Android Malware

While dynamic malware analysis methods generally provide better precision than purely static methods, they have the key drawback that they can only detect malicious behavior if it is executed during analysis. This requires inputs that trigger the malicious behavior to be applied during execution. All current methods, such as hard-coded tests, random fuzzing and concolic testing, can provide good coverage but are inefficient because they are unaware of the specific capabilities of the dynamic analysis tool. In this work, we introduce IntelliDroid, a generic Android input generator that can be configured to produce inputs specific to a dynamic analysis tool, for the analysis of any Android application. Furthermore, IntelliDroid is capable of determining the precise order that the inputs must be injected, and injects them at what we call the device-framework interface such that system fidelity is preserved. This enables it to be paired with full-system dynamic analysis tools such as TaintDroid. Our experiments demonstrate that IntelliDroid requires an average of 72 inputs and only needs to execute an average of 5% of the application to detect malicious behavior. When evaluated on 75 instances of malicious behavior, IntelliDroid successfully identifies the behavior, extracts path constraints, and executes the malicious code in all but 5 cases. On average, IntelliDroid performs these tasks in 138.4 seconds per application.