Eight years of rider measurement in the Android malware ecosystem: evolution and lessons learned

Despite the growing threat posed by Android malware, the research community is still lacking a comprehensive view of common behaviors and trends exposed by malware families active on the platform. Without such view, the researchers incur the risk of developing systems that only detect outdated threats, missing the most recent ones. In this paper, we conduct the largest measurement of Android malware behavior to date, analyzing over 1.2 million malware samples that belong to 1.2K families over a period of eight years (from 2010 to 2017). We aim at understanding how the behavior of Android malware has evolved over time, focusing on repackaging malware. In this type of threats different innocuous apps are piggybacked with a malicious payload (rider), allowing inexpensive malware manufacturing. One of the main challenges posed when studying repackaged malware is slicing the app to split benign components apart from the malicious ones. To address this problem, we use differential analysis to isolate software components that are irrelevant to the campaign and study the behavior of malicious riders alone. Our analysis framework relies on collective repositories and recent advances on the systematization of intelligence extracted from multiple anti-virus vendors. We find that since its infancy in 2010, the Android malware ecosystem has changed significantly, both in the type of malicious activity performed by the malicious samples and in the level of obfuscation used by malware to avoid detection. We then show that our framework can aid analysts who attempt to study unknown malware families. Finally, we discuss what our findings mean for Android malware detection research, highlighting areas that need further attention by the research community.Accepted manuscrip

SYSTEMATIC DISCOVERY OF ANDROID CUSTOMIZATION HAZARDS

The open nature of Android ecosystem has naturally laid the foundation for a highly fragmented operating system. In fact, the official AOSP versions have been aggressively customized into thousands of system images by everyone in the customization chain, such as device manufacturers, vendors, carriers, etc. If not well thought-out, the customization process could result in serious security problems. This dissertation performs a systematic investigation of Android customization’ inconsistencies with regards to security aspects at various Android layers. It brings to light new vulnerabilities, never investigated before, caused by the under-regulated and complex Android customization. It first describes a novel vulnerability Hare and proves that it is security critical and extensive affecting devices from major vendors. A new tool is proposed to detect the Hare problem and to protect affected devices. This dissertation further discovers security configuration changes through a systematic differential analysis among custom devices from different vendors and demonstrates that they could lead to severe vulnerabilities if introduced unintentionally