Jakob Bleier


Jakob Bleier
  • PreDoc Researcher
Publications (at TU Wien)
    • ART-assisted App Diffing: Defeating Dalvik Bytecode Shrinking, Obfuscation, and Optimization with Android's OAT Compiler
      Bleier, J., & Lindorfer, M. (2022, May 23). ART-assisted App Diffing: Defeating Dalvik Bytecode Shrinking, Obfuscation, and Optimization with Android’s OAT Compiler [Poster Presentation]. 43rd IEEE Symposium on Security and Privacy, San Francisco, United States of America (the).
      Abstract: Android aims to provide a secure and feature-rich, yet resource-saving platform for its applications (apps). To achieve these goals, the compilation to distributable packages shrinks, obfuscates, and optimizes the code by default. As an additional optimization, the Android Runtime (ART) nowadays compiles the app’s bytecode to native code on the device instead of executing it in the Dalvik VM. We study the effects of these changes in the Android build and runtime environment on the problem of calculating app similarity. We compare existing bytecode-based tools to our novel approach of using the recompiled (and optimized) binary form. We propose OATMEAL, an extensible framework to generate reliable ground truth for evaluating app similarity approaches and provide a benchmark dataset to the community. We built this dataset from open-source apps available on F-Droid in various configurations that optimize and obfuscate the bytecode. Using this dataset, we show the limitations of existing Android-specific bytecode analysis approaches when faced with the new optimizing R8 bytecode compiler. We further demonstrate how well BinDiff, a state-of-the-art binary-based alternative, works in scoring the similarity of apps. With OATMEAL, we provide the foundation for integrating and benchmarking further approaches, both for calculating the similarity between apps (based on bytecode or binary code), and for evaluating their robustness to evolving optimization and obfuscation techniques.
    • No Spring Chicken: Quantifying the Lifespan of Exploits in IoT Malware Using Static and Dynamic Analysis
      Al Alsadi, A. A., Sameshima, K., Bleier, J., Yoshioka, K., Lindorfer, M., van Eeten, M., & Hernández Gañán, C. (2022). No Spring Chicken: Quantifying the Lifespan of Exploits in IoT Malware Using Static and Dynamic Analysis. In Yuji Suga, Kouichi Sakurai, Xuhua Ding, & Kazue Sako (Eds.), ASIA CCS ’22: Proceedings of the 2022 ACM on Asia Conference on Computer and Communications Security (pp. 309–321). Association for Computing Machinery.
      DOI: 10.1145/3488932.3517408 Metadata
      Abstract: The Internet of things (IoT) is composed by a wide variety of software and hardware components that inherently contain vulnerabilities. Previous research has shown that it takes only a few minutes from the moment an IoT device is connected to the Internet to the first infection attempts. Still, we know little about the evolution of exploit vectors: Which vulnerabilities are being targeted in the wild, how has the functionality changed over time, and for how long are vulnerabilities being targeted? Understanding these questions can help in the secure development, and deployment of IoT networks. We present the first longitudinal study of IoT malware exploits by analyzing 17,720 samples collected from three different sources from 2015 to 2020. Leveraging static and dynamic analysis, we extract exploits from these binaries to then analyze them along the following four dimensions: (1) evolution of infection vectors over the years, (2) exploit lifespan, vulnerability age, and the time-to-exploit of vulnerabilities, (3) functionality of exploits, and (4) targeted IoT devices and manufacturers. Our descriptive analysis uncovers several patterns: IoT malware keeps evolving, shifting from simply leveraging brute force attacks to including dozens of device-specific exploits. Once exploits are developed, they are rarely abandoned. The most recent binaries still target (very) old vulnerabilities. In some cases, new exploits are developed for a vulnerability that has been known for years. We find that the mean time-to-exploit after vulnerability disclosure is around 29 months, much longer than for malware targeting other environments.