A critical component of a computer’s memory has been compromised, leaving many organizations vulnerable to attack. The stack, a region where temporary data is stored, has been targeted by malicious actors looking to hijack program execution.
The stack works like a physical pile of plates in your kitchen – new “plates” are added to the top and old ones are removed from the same spot when they’re no longer needed. This simple mechanism allows programs to call functions within functions and return to where they left off seamlessly. However, it’s precisely this simplicity that makes the stack a favorite target for attackers.
When an attacker can manipulate the stack, they gain control over a program’s execution flow. Imagine being able to insert malicious code into the middle of a trusted software application – you could make it do anything you want. This is exactly what attackers try to achieve when they target the stack.
A recent development in the world of cybersecurity tools aims to help users better understand how the stack works and why it’s so important to protect it. Xavier Mertens, a senior ISC handler and freelance cyber security consultant, has created a “stack simulator” that allows users to visualize what happens to the stack when code is executed.
The simulator, available on Mertens’ website, lets users select the architecture of their system (32-bit or 64-bit), choose a predefined set of instructions, and then step through the execution process. The impact on the stack and registers can be seen in real-time, making it easier to understand how the stack is manipulated.
The simulator also allows users to modify the predefined code and add their own instructions, making it an invaluable tool for malware analysis and reverse engineering. For those interested in learning more about malware analysis and how to use tools like this simulator effectively, Mertens will be teaching classes at SANS Tokyo Autumn 2026 and SANS Paris November 2026.
While the stack simulator is a powerful tool for cybersecurity professionals, it’s also a reminder that even seemingly simple mechanisms can hold great power – and danger. To protect yourself and your organization from these types of attacks, make sure to keep your systems up-to-date with the latest security patches, monitor your network closely for suspicious activity, and educate yourself on how to use tools like this simulator effectively.
In today’s fast-paced digital world, staying ahead of attackers requires a constant effort to learn and adapt. By understanding how the stack works and using tools like Mertens’ simulator, you can take a critical step towards protecting your organization from these types of threats.
Source: SANS ISC — 2026-07-10