With the recent increase in security breaches in embedded systems and IoT devices, it becomes increasingly important to search for vulnerabilities directly in binary executables in a cross-platform setting. However, very little has been explored in this domain. The existing efforts are prone to producing considerable false positives, and their results cannot provide explainable evidence for human analysts to eliminate these false positives. In this paper, we propose to extract conditional formulas as higher-level semantic features from the raw binary code to conduct the code search. A conditional formula explicitly captures two cardinal factors of a bug: 1) erroneous data dependencies and 2) missing or invalid condition checks. As a result, binary code search on conditional formulas produces significantly higher accuracy and provide meaningful evidence for human analysts to further examine the search results. We have implemented a prototype, XMATCH, and evaluated it using well-known software, including OpenSSL and BusyBox. Experimental results have shown that XMATCH outperforms the existing bug search techniques in terms of accuracy. Moreover, by evaluating 5 recent vulnerabilities, XMATCH provides clear evidence for human analysts to determine if a matched candidate is indeed vulnerable or has been patched.

Dynamic binary analysis is a prevalent and indispensable technique in program analysis. While several dynamic binary analysis tools and frameworks have been proposed, all suffer from one or more of: prohibitive performance degradation, a semantic gap between the analysis code and the program being analyzed, architecture/OS specificity, being user-mode only, and lacking APIs. We present DECAF, a virtual machine based, multi-target, whole-system dynamic binary analysis framework built on top of QEMU. DECAF provides Just-In-Time Virtual Machine Introspection and a plugin architecture with a simple-to-use event-driven programming interface. DECAF implements a new instruction-level taint tracking engine at bit granularity, which exercises fine control over the QEMU Tiny Code Generator (TCG) intermediate representation to accomplish on-the-fly optimizations while ensuring that the taint propagation is sound and highly precise. We perform a formal analysis of DECAF's taint propagation rules to verify that most instructions introduce neither false positives nor false negatives. We also present three platform-neutral plugins-Instruction Tracer, Keylogger Detector, and API Tracer, to demonstrate the ease of use and effectiveness of DECAF in writing cross-platform and system-wide analysis tools. Implementation of DECAF consists of 9,550 lines of C++ code and 10,270 lines of C code and we evaluate DECAF using CPU2006 SPEC benchmarks and show average overhead of 605 percent for system wide tainting and 12 percent for VMI.

Dynamic binary analysis is a prevalent and indispensable technique in program analysis. While several dynamic binary analysis tools and frameworks have been proposed, all suffer from one or more of: prohibitive performance degradation, semantic gap between the analysis code and the program being analyzed, architecture/OS specificity, being user-mode only, lacking APIs, etc. We present DECAF, a virtual machine based, multi-target, whole-system dynamic binary analysis framework built on top of QEMU. DECAF provides Just-In-Time Virtual Machine Introspection combined with a novel TCG instruction-level tainting at bit granularity, backed by a plugin based, simple-to-use event driven programming interface. DECAF exercises fine control over the TCG instructions to accomplish on-the-fly optimizations. We present 3 platform-neutral plugins - Instruction Tracer, Keylogger Detector, and API Tracer, to demonstrate the ease of use and effectiveness of DECAF in writing cross-platform and system-wide analysis tools. Implementation of DECAF consists of 9550 lines of C++ code and 10270 lines of C code and we evaluate DECAF using CPU2006 SPEC benchmarks and show average overhead of 605% for system wide tainting and 12% for VMI.