Polymorphism is challenging for novice programmers because it is an emergent consequence of multiple language features. OO polymorphism is critical to flexible software design, but no model currently explains student comprehension. In this research, students implemented the Strategy pattern to improve their comprehension of polymorphism, then were assessed by professional developers in whiteboard interviews. From these data, the authors work toward deriving a model of novice comprehension of polymorphism.

When new malware are discovered, it is important for researchers to analyze and understand them as quickly as possible. This task has been made more difficult in recent years as researchers have seen an increasing use of virtualization-obfuscated malware code. These programs are difficult to comprehend and reverse engineer, since they are resistant to both static and dynamic analysis techniques. Current approaches to dealing with such code first reverse-engineer the byte code interpreter, then use this to work out the logic of the byte code program. This outside-in approach produces good results when the structure of the interpreter is known, but cannot be applied to all cases. This paper proposes a different approach to the problem that focuses on identifying instructions that affect the observable behavior of the obfuscated code. This inside-out approach requires fewer assumptions, and aims to complement existing techniques by broadening the domain of obfuscated programs eligible for automated analysis. Results from a prototype tool on real-world malicious code are encouraging.

Analysis of software is essential to addressing problems of correctness, efficiency, and security. Existing source code analysis tools are very useful for such purposes, but there are many instances where high-level source code is not available for software that needs to be analyzed. A need exists for tools that can analyze assembly code, whether from disassembled binaries or from handwritten sources. This paper describes an equational reasoning system for assembly code for the ubiquitous Intel x86 architecture, focusing on various problems that arise in low-level equational reasoning, such as register-name aliasing, memory indirection, condition-code flags, etc. Our system has successfully been applied to the problem of simplifying execution traces from obfuscated malware executables.