Biblio

The current security mechanisms for Android apps, both static and dynamic analysis approaches, are insufficient for detection and prevention of the increasingly dynamic and sophisticated security attacks. Static analysis approaches suffer from false positives whereas dynamic analysis approaches suffer from false negatives. Moreover, they all lack the ability to efficiently analyze systems with incremental changes—such as adding/removing apps, granting/revoking permissions, and dynamic components’ communications. Each time the system changes, the entire analysis needs to be repeated, making the existing approaches inefficient for practical use. To mitigate their shortcomings, we have developed SALMA, a novel self-protecting Android software system that monitors itself and adapts its behavior at runtime to prevent a wide-range of security risks. SALMA maintains a precise architectural model, represented as a Multiple-Domain-Matrix, and incrementally and efficiently analyzes an Android system in response to incremental system changes. The maintained architecture is used to reason about the running Android system. Every time the system changes, SALMA determines (1) the impacted part of the system, and (2) the subset of the security analyses that need to be performed, thereby greatly improving the performance of the approach. Our experimental results on hundreds of real-world apps corroborate SALMA’s scalability and efficiency as well as its ability to detect and prevent security attacks at runtime with minimal disruption.

The number of malicious Android apps has been and continues to increase rapidly. These malware can damage or alter other files or settings, install additional applications, obfuscate their behaviors, propagate quickly, and so on. To identify and handle such malware, a security analyst can significantly benefit from identifying the family to which a malicious app belongs rather than only detecting if an app is malicious. To address these challenges, we present a novel machine learning-based Android malware detection and family-identification approach, RevealDroid, that operates without the need to perform complex program analyses or extract large sets of features. RevealDroid's selected features leverage categorized Android API usage, reflection-based features, and features from native binaries of apps. We assess RevealDroid for accuracy, efficiency, and obfuscation resilience using a large dataset consisting of more than 54,000 malicious and benign apps. Our experiments show that RevealDroid achieves an accuracy of 98% in detection of malware and an accuracy of 95% in determination of their families. We further demonstrate RevealDroid's superiority against state-of-the-art approaches. [URL of original paper: https://dl.acm.org/citation.cfm?id=3162625]

Like any other software engineering activity, assessing the security of a software system entails prioritizing the resources and minimizing the risks. Techniques ranging from the manual inspection to automated static and dynamic analyses are commonly employed to identify security vulnerabilities prior to the release of the software. However, none of these techniques is perfect, as static analysis is prone to producing lots of false positives and negatives, while dynamic analysis and manual inspection are unwieldy, both in terms of required time and cost. This research aims to improve these techniques by mining relevant information from vulnerabilities found in the app markets. The approach relies on the fact that many modern software systems, in particular mobile software, are developed using rich application development frameworks (ADF), allowing us to raise the level of abstraction for detecting vulnerabilities and thereby making it possible to classify the types of vulnerabilities that are encountered in a given category of application. By coupling this type of information with severity of the vulnerabilities, we are able to improve the efficiency of static and dynamic analyses, and target the manual effort on the riskiest vulnerabilities.

Proliferation of Android devices and apps has created a demand for applicable automated software testing techniques. Prior research has primarily focused on either unit or GUI testing of Android apps, but not their end-to-end system testing in a systematic manner. We present EvoDroid, an evolutionary approach for system testing of Android apps. EvoDroid overcomes a key shortcoming of using evolutionary techniques for system testing, i.e., the inability to pass on genetic makeup of good individuals in the search. To that end, EvoDroid combines two novel techniques: (1) an Android-specific program analysis technique that identifies the segments of the code amenable to be searched independently, and (2) an evolutionary algorithm that given information of such segments performs a step-wise search for test cases reaching deep into the code. Our experiments have corroborated EvoDroid’s ability to achieve significantly higher code coverage than existing Android testing tools.