Smartphone vendors are using multiple methods to kill processes of Android apps to reduce the battery consumption. This motivates developers to find ways to extend the liveness time of their apps, hence the name diehard apps in this paper. Although there are blogs and articles illustrating methods to achieve this purpose, there is no systematic research about them. What’s more important, little is known about the prevalence of diehard apps in the wild. In this paper, we take a first step to systematically investigate diehard apps by answering the following research questions. First, why and how can they circumvent the resource-saving mechanisms of Android? Second, how prevalent are they in the wild? In particular, we conduct a semi-automated analysis to illustrate insights why existing methods to kill app processes could be evaded, and then systematically present 12 diehard methods. After that, we develop a system named DiehardDetector to detect diehard apps in a large scale. The experimental result of applying DiehardDetector to more than 80k Android apps downloaded from Google Play showed that around 21% of apps adopt various diehard methods. Moreover, our system can achieve high precision and recall.

Hao Zhou

The Hong Kong Polytechnic University

China

Haoyu Wang

Beijing University of Posts and Telecommunications, China

China

Yajin Zhou

Zhejiang University

Xiapu Luo

The Hong Kong Polytechnic University

Yutian Tang

ShanghaiTech University

China

Lei Xue

The Hong Kong Polytechnic University

Ting Wang

Penn State University

The UI driven nature of Android apps has motivated the development of automated UI analysis for various purposes, such as app analysis, malicious app detection, and app testing. Although existing automated UI analysis methods have demonstrated their capability in dissecting apps’ UI, little is known about their effectiveness in the face of app protection techniques, which have been adopted by more and more apps. In this paper, we take a first step to systematically investigate UI obfuscation for Android apps and its effects on automated UI analysis. In particular, we point out the weaknesses in existing automated UI analysis methods and design 9 UI obfuscation approaches. We implement these approaches in a new tool named UIObfuscator after tackling several technical challenges. Moreover, we feed 3 kinds of tools that rely on automated UI analysis with the apps protected by UIObfuscator, and find that their performances severely drop. This work reveals limitations of automated UI analysis and sheds light on app protection techniques.

Hao Zhou

The Hong Kong Polytechnic University

China

Ting Chen

University of Electronic Science and Technology of China

Haoyu Wang

Beijing University of Posts and Telecommunications, China

China

Le Yu

The Hong Kong Polytechnic University

Xiapu Luo

The Hong Kong Polytechnic University

Ting Wang

Penn State University

Wei Zhang

Nanjing University of Posts and Telecommunications

Mobile operating systems evolve quickly, frequently updating the APIs that app developers use to build their apps. Unfortunately, API updates do not always guarantee backward compatibility, causing apps to not longer work properly or even crash when running with an updated system. This paper presents FILO, a tool that assists Android developers in resolving backward compatibility issues introduced by API upgrades. FILO both suggests the method that needs to be modified in the app in order to adapt the app to an upgraded API, and reports key symptoms observed in the failed execution to facilitate the fixing activity. Results obtained with the analysis of 12 actual upgrade problems and the feedback produced by early tool adopters show that FILO can practically support Android developers. FILO can be downloaded from https://gitlab.com/learnERC/filo, and its video demonstration is available at https://youtu.be/WDvkKj-wnlQ.

Marco Mobilio

University of Milano Bicocca

Italy

Oliviero Riganelli

University of Milano-Bicocca, Italy

Daniela Micucci

University of Milano-Bicocca, Italy

Italy

Leonardo Mariani

University of Milano Bicocca

Italy