A recent tool has been released to help students and cybersecurity professionals alike better understand how a program’s memory stack works, a critical component of malware analysis. The “stack simulator” created by Xavier Mertens is an interactive assembly editor that visualizes the impact on the stack and registers when code is executed.
The stack is a fundamental concept in computer science, used to store temporary data such as local variables and return addresses. Think of it like a pile of plates: new plates are added to the top, and only the top plate can be removed. Programs use this “last in, first out” principle to keep track of what they’re doing, allowing functions to be called within other functions without getting lost.
However, when a stack grows too large or is overwritten with unexpected data, it becomes a favorite target for attackers looking to hijack a program’s execution flow. This can lead to malicious code being executed, potentially causing serious damage. Understanding how the stack works is therefore crucial for malware analysis and reverse engineering.
The stack simulator tool allows users to select an architecture (32- or 64-bit), choose from pre-defined instructions, and click “Step” to see the impact on the stack and registers. Users can also modify the predefined ASM code and add their own instructions. This interactive approach makes it easier for students and professionals to visualize how the stack works, reducing the complexity of assembly language and malware analysis.
The tool is available on Mertens’ website, along with information on his upcoming classes on malware analysis. SANS offers courses such as FOR610, which covers introductory material on assembly and stack manipulation. For those interested in taking their skills to the next level, there are training events scheduled for Tokyo and Paris later this year.
While the stack simulator is primarily designed for educational purposes, it can also be a valuable resource for cybersecurity professionals looking to improve their understanding of malware analysis. By visualizing how the stack works, users can better identify potential vulnerabilities and develop more effective strategies for detecting and mitigating attacks.
To take advantage of the stack simulator tool, visit Mertens’ website and explore the interactive assembly editor. With its user-friendly interface and extensive instructions, it’s an excellent resource for anyone looking to improve their knowledge of malware analysis and reverse engineering.
Source: SANS ISC — 2026-07-10