Hacking DNS

Info

Level: Intermediate
Presenter: Eli the Computer Guy
Date Created: November 1, 2010
Length of Class: 45 Minutes
Tracks

Hacking
Computer Security /Integrity
Prerequisites

Knowledge of TCP/IP and Domain Name Resolution
Purpose of Class

This class teaches students how use DNS to redirect computer or network users to alternate websites or servers for security or malicious purposes.
Topics Covered

How DNS Works
Editing the HOSTS file
Alternate Public DNS
Planning a DNS Hack
Reasons to Hack DNS
Class Notes

Introduction
DNS resolves Domain Names to IP Addresses
Warning: Use at your own risk
DNS
HOSTS file is the local file that resolves Domain Names
Windows Location = C:\Windows\System32\drivers\etc
Example = 10.1.10.2 www.elithecomputerguy.com
In Vista/ Windows 7 First Open Notepad using "Run as Administrator" and then open the HOSTS file. Otherwise you will not be able to save your edits.
Computers FIRST try to Resolve a Domain Name with the HOSTS file, they then Go To the LOCAL DNS Server, and then they Query the PUBLIC DNS Server. If any server has a record the computer does not ask any other sources. SO if the HOSTS file has a record the computer uses that record and stops.
Using Alternate DNS
You do not have to use the Public DNS IP Addresses that your ISP gave you. You can use Alternate Public DNS Servers.
The benefit of using a server like OpenDNS.org is that they will prevent Domain Names for malicious websites from resolving. This is a HUGE security tool.
You can create your own Public DNS Server for Good/ Bad Purposes.
The DNS Attack
HOSTS file can be compromised either through manual editing, or through scripting. If users are logged in as USERS vs. ADMINISTRATORS there is far less chance that a script will be able to modify the HOSTS file.
By Wardriving or Plugging Into an Unsecured Network Jack You May be able to Hack the DNS Server. Routers/ Modems with default passwords are easy to Hack.
A clever, well disguised DNS Hack is very difficult to detect once it has been successfully implemented, and it is moderately difficult to circumvent if it is done by a network administrator to secure a network.
Final Thoughts
Hacking DNS is the EASIEST way to either protect or attack a network or computer

Category:

Science & Technology

Tags:

• Hacking
• DNS

[cazyblood3]

DNS is like fingerprint

[elithecomputerguy]

@cazyblood3 no... the MAC address would be like the fingerprint... MAC addresses are unique for EVERY network interface in the world (supposedly)

[megaton12]

@elithecomputerguy MAC addresses can be easily spoofed.

[elithecomputerguy]

@megaton12 true, but that will be another class....

[F145H220]

OK so what if i search for google in google.com and then i click the first result of the search .Will it work the same way as entering google.com in the address bar does?

[elithecomputerguy]

@F145H220 yes because the search result is still pointing to the domain name, and the domain name resolution has been redirected by you.

[myonlynick]

bored watching the entire video?

Fast results: click to 21:20

[riz1q2]

You should show DNS poisoning at more advance level.

Your videos are a GREAT refresher.....and I am sure many of rookies are appreciating it very much. I have camera phobia, other wise i would do these videos too :) keep up the good work

[sambhajiipar]

wow



[Inzolity]

Thank Eli, now I know how to prevent these kinds of attacks on my domain, and keep it secure! :)

[maxthepwner]

@cazyblood3 I do believe you mean DNA. Domain Name Service does not equal finger print.

[WildMohsen]

thumbs up :)

keep up the good work

waiting for more videos :D

[d45htriton]

Very informative and educational. Great job man.

[TrainingTopSecr3t]

Thats windows xp

[onlyme0349]

ty i was looking for someone to explain things clearly altough its a long vid its really educativ and easy to remember

[mohahahaish]

hello can someone send me a link , so i learn about dns then watch this video im a beginner ,,,,, please help , thanks a lot .