How to reverse engineer DNS based blocksInformation wants to be freeThis is a Hades Security Intelligence release! Assume your ISP is blocking certain sites in DNS based filters. This method describeshow to reverse engineer the block and find out which adresses your ISP is blocking. Loop through IPV4 space from 0.0.0.0 to 255.255.255.255 For each IP adress lookup the IP in the ISP DNS and a Public DNS service like 220.127.116.11 For each lookup compare the name lookup result. If the name lookup differs you have an IP which your internet provider is blocking. 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 @18.104.22.168 +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.