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Jakstab

Overview

Jakstab is an Abstract Interpretation-based, integrated disassembly and static analysis framework for designing analyses on executables and recovering reliable control flow graphs. It is designed to be adaptable to multiple hardware platforms using customized instruction decoding and processor specifications. It is written in Java, and in its current state supports x86 processors and 32-bit Windows PE or Linux ELF executables.

Jakstab translates machine code to a low level intermediate language on the fly as it performs data flow analysis on the growing control flow graph. Data flow information is used to resolve branch targets and discover new code locations. Other analyses can either be implemented in Jakstab to run together with the main control flow reconstruction to improve precision of the disassembly, or they can work on the resulting preprocessed control flow graph.

The most detailed description of the entire system so far is contained in Johannes Kinder`s dissertation:

• Johannes Kinder: Static Analysis of x86 Executables. Technische Universität Darmstadt, 2010. PDF

Running Jakstab

Jakstab is invoked via the command line, it comes with both a Windows and a Unix shell script for setting the correct classpath. The package contains a set of examples for unit testing, you can try it out on those by running

jakstab -m input/helloworld.exe

for a default Bounded Address Tracking run on the helloworld executable, or by running

jakstab -m input/jumptable.exe --cpa xfi

for analyzing a jumptable example with Bounded Address Tracking, forward expression substitution, and interval analysis. It is still a research prototype, so all interfaces are likely to change with new versions without further notice. Documentation is still sparse, but will hopefully improve over time.

Outputs

After finishing analysis, Jakstab creates the following files:

• filename_jak.asm - A disassembly with all reachable instructions
• filename_cfa.dot - A CFG in the intermediate language, instruction by instruction
• filename_asmcfg.dot - A CFG of assembly instructions, in basic blocks

Supported Analyses

The analyses (CPAs) that should be working correctly are:

• Bounded Address Tracking (x) (see FMCAD'10)
• VPC-lifted Bounded Address Tracking (v) (see WCRE'12)
• Constant Propagation (c)
• Forward Expression Substitution (f)
• Interval Analysis (i)
• K-Set Analysis (k)

Publications

The following publications, sorted chronologically, describe specific aspects of Jakstab, or applications and extensions of it.

The CAV 2008 tool paper describes an early implementation of Jakstab, which was based on iterative constant propagation and branch resolution:

• Johannes Kinder, Helmut Veith. Jakstab: A Static Analysis Platform for Binaries. In Proceedings of the 20th International Conference on Computer Aided Verification (CAV 2008), vol. 5123, Lecture Notes in Computer Science, Springer, July 2008, pp. 423–427.

Our VMCAI 2009 paper introduces a generic framework for disassembly and control flow reconstruction guided by data flow analysis and defines the theoretical background for Jakstab. The framework is not fixed in its choice of domain, but allows to combine control flow reconstruction with any data flow analysis that provides abstract evaluation of expressions:

• Johannes Kinder, Helmut Veith, Florian Zuleger. An Abstract Interpretation-Based Framework for Control Flow Reconstruction from Binaries. In Proceedings of the 10th International Conference on Verification, Model Checking, and Abstract Interpretation (VMCAI 2009), vol. 5403, Lecture Notes in Computer Science, Springer, January 2009, pp. 214–228.

In FMCAD 2010, we give an overview on the Jakstab architecture and describe Bounded Address Tracking, a practical abstract domain used for control flow reconstruction and verification of API usage specifications on device driver binaries:

• Johannes Kinder, Helmut Veith. Precise Static Analysis of Untrusted Driver Binaries. In Proceedings of the 10th International Conference on Formal Methods in Computer-Aided Design (FMCAD 2010), October 2010, pp. 43–50.

In our paper at VMCAI 2012, we give a reformulation of control flow reconstruction using parameterized semantics, and show how it can be extended to accomodate under-approximations derived from concrete execution traces. A prototype implementation shows that under-approximations allow to reconstruct useful CFGs when the over-approximation would have to conservatively over-approximate indirect jump targets.

• Johannes Kinder, Dmitry Kravchenko. Alternating Control Flow Reconstruction. In Proceedings of the 13th International Conference on Verification, Model Checking, and Abstract Interpretation (VMCAI 2012), vol. 7148, Lecture Notes in Computer Science, Springer, January 2012, pp. 267-282.

The WCRE 2012 paper proposes a method for using Jakstab to analyze binaries that have been protected using virtualization-obfuscation.

• Johannes Kinder. Towards Static Analysis of Virtualization-Obfuscated Binaries. In Proceedings of the 19th Working Conference on Reverse Engineering (WCRE 2012), IEEE, October 2012.