Then, if the variable type and base address are known, you can assign the structure type to the relevant variable so that accesses are more readable instead of raw offsets.

For example, instead of just seeing that the program reads from [rcx+4], you can recognize that it is reading the second field of the structure.

This also simplifies the analysis of subsequent functions because you do not have to calculate from the beginning which memory section each offset refers to each time.

Exercise:

Suppose you find these instructions in a binary file.

Asm

mov eax, dword ptr [rbx]

cmp eax, 0

mov ecx, dword ptr [rbx+8]

mov byte ptr [rbx+12], 1

Based on these instructions, determine

what memory offsets are used and what is the size of each access.

What types of fields are possible in this Offsets exist

Why can't we still say with certainty what fields the original structure has?

The main point of this section is that in reverse engineering you don't need to know the original structure from the start. By gathering evidence from offsets, access sizes, and how data is used, you can build a plausible model of the memory structure step by step

@reverseengine