1 Introduction
According to Statista [35], Android was the most widely used smartphone OS in the world with a market share of 87.9% at the end of the second quarter of 2017. Another Statista report [36] shows that Android had more than 3 times as many vulnerabilities reported in it as the nearest competing mobile operating system, iOS. Moreover, a Kaspersky Labs report of April 2018 specifies the existence of 94,368 mobile banking trojans [32], showing that ABTs are rapidly and dynamically evolving in their attacks. These three statistics collectively suggest that the problem of detecting Android Banking Trojans (ABTs for short) is of enormous importance.