R-PackDroid: API package-based characterization and detection of mobile ransomware.

Ransomware has become a serious and concrete threat for mobile platforms and in particular for Android. In this paper, we propose R-PackDroid, a machine learning system for the detection of Android ransomware. Differently to previous works, we leverage information extracted from system API packages, which allow to characterize applications without specific knowledge of user-defined content such as the application language or strings. Results attained on very recent data show that it is possible to detect Android ransomware and to distinguish it from generic malware with very high accuracy. Moreover, we used R-PackDroid to flag applications that were detected as ransomware with very low confidence by the VirusTotal service. In this way, we were able to correctly distinguish true ransomware from false positives, thus providing valuable help for the analysis of these malicious applications.