How to reverse engineer DNS based filters

How to reverse engineer DNS based blocks

Information wants to be free

This is a Hades Security Intelligence release!

Assume your ISP is blocking certain sites in DNS based filters. This method describes

how to reverse engineer the block and find out which adresses your ISP is blocking.

1. Loop through IPV4 space from 0.0.0.0 to 255.255.255.255
2. For each IP adress lookup the IP in the ISP DNS and a Public DNS service like 8.8.8.8
3. For each lookup compare the name lookup result. If the name lookup differs you have an IP which your internet provider is blocking.
4. Please leak these reverse list to Wikileaks or other suitable service.

#!/usr/bin/python
#ipv4 = A.B.C.D
import os
import sys

aarg=146
barg=int(sys.argv[-1])

f=open('iplist-%i.%i.txt' % (aarg,barg),'a')
for a in range(aarg,aarg+1):
for b in range(barg,barg+1):
for c in range(0,256):
for d in range(0,256):
ip = "%s.%s.%s.%s" % (a,b,c,d)
print ip
dnsresult = os.popen("dig +short -x %s.%s.%s.%s" % (a,b,c,d)).readline()
gresult = os.popen("dig @8.8.8.8 +short -x %s.%s.%s.%s" % (a,b,c,d)).readline()
print dnsresult.rstrip('\n')
print gresult.rstrip('\n')
f.write("%s:%s:%s\n" % (ip,dnsresult.rstrip('\n'),gresult.rstrip('\n')))
f.close()

By Acdhead of HSI

Political end notes:

• Bankers with fractional reserve banking steal from the common people by extracting huge bonuses and socializing debt watch out for us we are coming for you! We hackers see through your systematic theft. Politicians enabling this theft by taking party contributions to lower cash reserve ratios and looking the other way is corrupt.
• Politicians which wants to censor the Internet, you do not belong in a state which promotes freedom of speech.

for gui firends:
https://code.google.com/p/dnsprobe/

multi threading dns check agains a cenure free dns

itis open saourece
and form anon for anon