Leveraging Windows internals for malware development

The Windows API allows developers to interact with the Windows operating system via their applications. For instance, if an application needs to display something on the screen, modify a file, or download something from the internet, all of these tasks can be accomplished through the Windows API. Microsoft provides extensive documentation for the Windows API, which can be viewed on MSDN.

Practical example

Here is a straightforward C program that uses the Windows API to retrieve and display the name of the current user. Remember that, while this program is not inherently harmful, comprehending these principles can serve as a stepping stone to the development of more complex (potentially harmful) programs. Use this information responsibly at all times:

#include <windows.h>
#include <stdio.h>
int main() {
  char username[UNLEN + 1];
  DWORD username_len = UNLEN + 1;
  GetUserName(username...