No abstract

Current static analysis techniques for Android applications operate at the Java level-that is, they analyze either the Java source code or the Dalvik bytecode. However, Android allows developers to write code in C or C++ that is cross-compiled to multiple binary architectures. Furthermore, the Java-written components and the native code components (C or C++) can interact. Native code can access all of the Android APIs that the Java code can access, as well as alter the Dalvik Virtual Machine, thus rendering static analysis techniques for Java unsound or misleading. In addition, malicious apps frequently hide their malicious functionality in native code or use native code to launch kernel exploits. It is because of these security concerns that previous research has proposed native code sandboxing, as well as mechanisms to enforce security policies in the sandbox. However, it is not clear whether the large-scale adoption of these mechanisms is practical: is it possible to define a meaningful security policy that can be imposed by a native code sandbox without breaking app functionality? In this paper, we perform an extensive analysis of the native code usage in 1.2 million Android apps. We first used static analysis to identify a set of 446k apps potentially using native code, and we then analyzed this set using dynamic analysis. This analysis demonstrates that sandboxing native code with no permissions is not ideal, as apps' native code components perform activities that require Android permissions. However, our analysis provided very encouraging insights that make us believe that sandboxing native code can be feasible and useful in practice. In fact, it was possible to automatically generate a native code sandboxing policy, which is derived from our analysis, that limits many malicious behaviors while still allowing the correct execution of the behavior witnessed during dynamic analysis for 99.77% of the benign apps in our dataset. The usage of our system to generate policies would reduce the attack surface available to native code and, as a further benefit, it would also enable more reliable static analysis of Java code. Permission to freely reproduce all or part of this paper for noncommercial purposes is granted provided that copies bear this notice and the full citation on the first page. Reproduction for commercial purposes is strictly prohibited without the prior written consent of the Internet Society, the first-named author (for reproduction of an entire paper only), and the author's employer if the paper was prepared within the scope of employment.

No abstract

The ubiquity of Internet-connected devices motivates attackers to create malicious programs (malware) to exploit users and their systems. Malware detection requires a deep understanding of their possible behaviors, one that is detailed enough to tell apart suspicious programs from benign, legitimate ones. A step to effectively address the malware problem leans toward the development of an ontology. Current efforts are based on an obsolete hierarchy of malware classes that defines a malware family by one single prevalent behavior (e.g., viruses infect other files, worms spread and exploit remote systems autonomously, Trojan horses disguise themselves as benign programs, and so on). In order to address the detection of modern, complex malware families whose infections involve sets of multiple exploit methods, we need an ontology broader enough to deal with these suspicious activities performed on the victim's system. In this paper, we propose a core model for a novel malware ontology that is based on their exhibited behavior, filling a gap in the field.

Malicious code (malware) that spreads through the Internet-such as viruses, worms and trojans-is a major threat to information security nowadays and a profitable business for criminals. There are several approaches to analyze malware by monitoring its actions while it is running in a controlled environment, which helps to identify malicious behaviors. In this article we propose a tool to analyze malware behavior in a non-intrusive and effective way, extending the analysis possibilities to cover malware samples that bypass current approaches and also fixes some issues with these approaches.

Bankers" are special types of malware whose targets are Internet banking users, mainly to obtain their credentials. Banker infections cause losses of billions of dollars worldwide. Thus, better understanding and detection of bankers is required. Due to their interactive nature, obtaining bankers' behaviors can be a difficult task for current dynamic analyzers. Also, existing tools specially crafted to detect bankers are usually limited to a specific type. In this article, we propose BanDIT, a dynamic analysis system that identifies behavior related to bankers combining visual analysis, network traffic pattern matching and filesystem monitoring. We analyzed over 1,500 malware samples to identify those whose target were online banks and reported the compromised IP and e-mail addresses found. We present an evaluation of their behavior and show that BanDIT was able to identify 98.8% of bankers in a manually labeled banker samples set.

No abstract

Abstract. Malicious programs pose a major threat to Internet-connected systems, increasing the importance of studying their behavior in order to fight against them. In this paper, we propose definitions to the different types of behavior that a program can present during its execution. Based on those definitions, we define suspicious behavior as the group of actions that change the state of a target system. We also propose a set of network and system-level dangerous activities that can be used to denote the malignity in suspicious behaviors, which were extracted from a large set of malware samples. In addition, we evaluate the malware samples according to their suspicious behavior. Moreover, we developed filters to translate from lower-level execution traces to the observed dangerous activities and evaluated them in the context of actual malware.