A Hacker’s Live CD

Today penetration testing is becoming an important procedure for companies who want their network to be secure. For this reason more and more security consultants are looking for an operating system made for penetration testing. This is where Backtrack comes in handy.

Gained access to a Windows computer through the metasploit framework on Backtrack

Backtrack 3

Backtrack is a Live CD based on Slackware. It is the result of the merger of WHAX and Auditor Security Linux which were both Live CDs made for computer security professionals. Therefore it’s no surprise that Backtrack has a huge collection with more than 300 security and forensics tools. Backtrack was made for security penetration testers and for that reason all the tools are organized according to the workflow of security professionals. The tight integration of these tools into the Live CD make hacking even easier, e.g. by entering one command you will get the latest milw0rm exploits which you could use for an attack. For more information take a look at the official Backtrack homepage.

You can download Backtrack here, it is really worth taking a look at. Tell me what think about it.

Forward DNS Bruteforcing with Python

DNS is one of the most important protocols on the internet. If you visited a homepage like this one your computer probably used DNS. The domain name system is used to associate ip addresses with certain domains, e.g. Google’s ip address is 64.233.167.99 and it is associated with google.com. So whenever you type google.com in your browser your computer actually looks up the ip address of it and further connects to it.
Forward DNS Bruteforcing
Forward DNS bruteforcing is method which uses DNS to find out about potential services of a domain. The concept is very simple. A lot of domains now a days have subdomains in the case of Google it could be mail.google.com. Here mail is a subdomain of Google thus it needs to have a certain ip address otherwise it wouldn’t be available over the internet. So what Forward DNS bruteforcing actually does is query DNS servers for subdomains and through the response you know whether it exists or not. Let’s take a look at an example.

Example
Let’s say we want to know whether Google has a VPN service available. You could try to forward bruteforce Google by querying a DNS server for vpn.google.com. Now if it exists it has to have an ip address and we would get it through the query.

Python DNS Bruteforcing Script
Now I coded this little script in Python. It actually does the same as stated above. I am not sure whether it works under Windows since it uses the “host” command to query for domains but it should work well under Linux. When you run the script you need to provide a file and a domain. The file should be just a list of subdomain names (e.g. vpn, mail, pop etc.) which you want to forward bruteforce. The domain is obvisiously the domain you want to bruteforce. Here is the source code of the script:

#!/usr/bin/env python

import os, sys, commands

if len(sys.argv) < 3:

print ” DNS Bruteforce lookup on the domain by”
print ” adding the names in the file to the domain”
print “Usage: %s <file> <host>” % sys.argv[0]
sys.exit(0)

file = sys.argv[1]
fh = open(file, “r”).readlines()
try:

• • val = name[0:len(name)-2]
    val = name[0:len(name)-1]
    print var
    print “Shutting down application …”
    sys.exit(0)

  if name.endswith(“\r\n”):else:

  var = commands.getoutput(“host %s.%s ” % (val, sys.argv[2]))
  if not “not found” in var:

  except KeyboardInterrupt:

for name in fh:

Where To Get Great Free Linux Ebooks

Today there is so much information on the internet that you do not know where to start looking for it. The most obvious place to look for information is in search engines. There you enter your keywords and get maybe 1,000,000 web sites related to your keywords?! This is the problem with the internet and probably the main reason why ebooks emerged. Ebooks provide you with concise information about a special topic. You have to pay for most of the ebooks on the web today but there are still some great ebooks available for free, you just have to know where to get them.
Since this blog is about computer security I am going to provide you with mostly security and network related books. If you want to get other free ebooks take a look at Wowio or search Google for “free ebooks.”

Great Linux Ebook Web Site
I recently found a really great web site which has a whole lot of Linux guides (ebooks). Take a look at it. It is called The Linux Documentation Project and their main goal is to provide detailed Linux tutorials. For example if you want to learn about Linux System Administration take a look at this guide. You can choose to download them or read them online.

Another web site at which you might want to take a look at would be Astalavista. They have a whole lot of whitepapers on computer security. Furthermore there are some guides and tutorials provided by users which might interest you.

Tell me what you think about it.