一句话:对 Android 应用的自我隐藏行为进行刻画,并提出静态分析检测方法以区分恶意与良性应用。
论文关注 Android 应用中刻意隐藏自身活动或清除痕迹的“自我隐藏行为”(SHB),此类行为此前仅在恶意软件调查中被附带提及,缺乏系统研究。作者首先给出 SHB 的详细刻画,涵盖隐藏应用存在/活动、拦截通话短信、删除日志记录等;进而设计一组静态分析及检测器,用于识别 SHB 并区分良性/恶意应用。在 9,452 个 Android 应用(含良性、恶意)上评估,揭示 12 类 SHB 的出现频率,恶意应用平均每应用 1.5 种 SHB;良性应用亦存在该行为。检测恶意与良性应用的综合 F 值为 87.19%,单应用平均分析耗时约 37 秒。
Applications (apps) that conceal their activities are fundamentally deceptive; app marketplaces and end-users should treat such apps as suspicious. However, due to its nature and intent, activity concealing is not disclosed up-front, which puts users at risk. In this paper, we focus on characterization and detection of such techniques, e.g., hiding the app or removing traces, which we call "self hiding behavior" (SHB). SHB has not been studied per se - rather it has been reported on only as a byproduct of malware investigations. We address this gap via a study and suite of static analyses targeted at SH in Android apps. Specifically, we present (1) a detailed characterization of SHB, (2) a suite of static analyses to detect such behavior, and (3) a set of detectors that employ SHB to distinguish between benign and malicious apps. We show that SHB ranges from hiding the app's presence or activity to covering an app's traces, e.g., by blocking phone calls/text messages or removing calls and messages from logs. Using our static analysis tools on a large dataset of 9,452 Android apps (benign as well as malicious) we expose the frequency of 12 such SH behaviors. Our approach is effective: it has revealed that malicious apps employ 1.5 SHBs per app on average. Surprisingly, SH behavior is also employed by legitimate ("benign") apps, which can affect users negatively in multiple ways. When using our approach for separating malicious from benign apps, our approach has high precision and recall (combined F-measure = 87.19%). Our approach is also efficient, with analysis typically taking just 37 seconds per app. We believe that our findings and analysis tool are beneficial to both app marketplaces and end-users.