Payload Storage

Payloads can be stored in .text, .data, or .rsrc .text stored payloads are executable by default, .data and .rsrc stored payloads require you to make the memory executable at runtime.

.text

Put the payload into a function e.g. main function.

int main(int argc, char *argv[]){

	unsigned char shellcode[] = {
		// shellcode here
	};
	
	// everything else main does
} 

.data

Tell the compiler that your payload is read only data, accomplished by creating a global variable holding your payload.

unsigned char shellcode[] = {
	// shellcode here
};
unsigned int shellcode_len = <shellcode_len>;

int main(int argc, char *argv[]){
  // main contents
} 

.rsrc

Create a small file holding your payload and tell the compiler it should be part of the resources section, use API to reach into the resources section and extract the payload from there. In the folder, have your payload in a binary format, in this case it would be calc.ico.

main.c

#include "resources.h"

int main(int argc, char *argv[]){
	HRSRC res;
	HGLOBAL resHandle;
	unsigned char * payload;
	unsigned int payload_len;
	
	res = FindResource(NULL, MAKEINTRESOURCE(FAVICON_ICO), RT_RCDATA); // return handle of FAVICON_ICO resource
	resHandle = LoadResource(NULL, res); // returns handle to module containing our resource
	payload = (char *) LockResource(resHandle); // returns pointer to first byte of our payload
	payload_len = SizeofResource(NULL,res); // returns the size of the payload

	// everything else main does
} 

resources.h

#define FAVICON_ICO 100

resources.rc

#include "resources.h"

FAVICON_ICO RCDATA calc.ico