Win32.Xorist - Coded by Xylitol

Introduction/Explaination:
This is a basic Xorist example, coded with MASM32.
As this type of things can be used for doing a 'black hat' money profit and are for the moment of interest by the masses, i've voluntary 'clamped' my code (no recursive function for directories).
This simple Xorist will show you how to encode JPG images in a folder, encrypted images can be recovered by pressing once again the encrypt button.
To go further you can implement a RSA function, there is plenty of ' big numbers' libraries to do that in assembly language.

This is not really in the old-school vs spirit, but thought this type of code can interest some people.. at least to understand how this type of malware can work.
Note that i used WinASM as IDE, i've included the .wap project file.