BackTrack – Testing Wireless Network Security

BackTrack – Testing Wireless Network Security

BackTrack – Testing Wireless

Network Security

Installing and Configuring

BackTrack

In this chapter, we are going to look at the following with respect to using BackTrack:

• Downloading and configuring BackTrack

• Installing BackTrack

• Updating BackTrack

• Validating the interfaces

• Customizing Gnome

• Creating a virtual machine

Before we focus on downloading, installing and configuring Backtrack,

I will provide a brief introduction to Backtrack. The BackTrack distribution is

actually a combination of two different distributions merged together. There

are many distributions that are available, but BackTrack distribution has been

created specifically for professional security and penetration testing. The BackTrack

distribution was the result of a merger between the two distributions Whax and

Auditor. For a brief on some of the distributions, including Auditor, you can find

a presentation that I gave at Black Hat in 2005 via this link:

http://www.blackhat.com/presentations/bh-usa-05/bh-us-05-cardwell.pdf

The name BackTrack comes from the term backtracking, which is the name of a

search algorithm.

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Downloading and configuring BackTrack

The BackTrack distribution comes in a variety of formats; the format you choose

is largely a matter of personal preference and your comfort with creating virtual

machines. Each one of the distributions has the same tools; they only differ in

the utilities that are available with the desktop once you enter the windowing

environment. The available distributions come in either a 32-bit or 64-bit distribution;

most users will be fine with 32-bit distributions. The main consideration is the amount

of random accessory memory (RAM) you will have available for the installation. If you

can allocate more than 4 GB of RAM, you can choose the 64-bit distribution; if not then

go with the 32-bit option. BackTrack will work with as little as 1 GB of RAM, but the

tools you use within it might need more, so 2 GB or more is recommended.

An important point to note is that you should always verify the image files

of anything you download. That is why there is an MD5 hash for each of the

downloads. If you do not know how to do this, you can do a search for it on the

Internet. There are a number of tools that can be downloaded to assist you with

verifying the hash of a file.

The ISO file allows you to take the image and burn it to a DVD, allowing you to boot

from the image and run BackTrack from the DVD. Alternatively, you can also mount

the image using a virtualization tool and boot it that way.

For our purposes, we will use the virtual machine, as it is easy to use and has been

configured with the tools; this allows you to copy and paste within the VM and have

a full screen virtual environment. We will also include steps later in the chapter for

booting the ISO image in VMware Workstation, as that will result in the identical

interface that will be experienced when booting from a DVD image. VMware

Workstation was one of the first virtual environment software products and allows

us to run multiple computers on one machine.

BackTrack can be downloaded from its official website at http://www.BackTracklinux.

org/downloads/. Once you go to the website, you will see that there is a

registration request there; this is optional, and downloading the distribution is not

required. On the Downloads page, you will see a drop-down window that you will

use to select the version of the distribution that you want to download. Once you

click on the drop-down window, the other windows will be populated as displayed

in the next screenshot:

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We will be using the BackTrack 5 R3 distribution with the window manager Gnome

(32-bit) and the VMware image installation for the book; download the image, and

then we will continue with the installation.

Installing BackTrack

Once you have downloaded the image, you will need to have certain VMware

software to run the image; you can get the software from www.vmware.com. VMware

Player is smaller with fewer options, although VMware Workstation contains many

features. Both versions have a trial version available, and it is recommended that you

select one and try it out. For this book, we are using VMware Workstation Version 9

as that is the latest version as of this writing. To access the software downloads page,

go to http://www.vmware.com/products/workstation/index.html. VMware

software allows you to perform many functions in a virtual environment, and this

can be an additional security measure for you. If you are using a Mac, you will need

to download VMware Fusion for that; refer to http://www.vmware.com/products/

fusion/overview.html. Also, if you want to use the ISO image to create a DVD and

boot from that, you can do that too. The way in which we start BackTrack is the only

thing that differs from the other distributions; once they start, they all require the

same number of steps to be configured and used.

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You may also want to note here that there are more virtualization products than

VMware, and if you want to try others, you may; some of the popular, free ones are:

• VirtualBox – https://www.virtualbox.org/wiki/Downloads

• Xen – http://www.xen.org/products/downloads.html

• Hyper-V – http://www.microsoft.com/en-us/server-cloud/hyper-vserver/

default.aspx

Hyper-V requires you to have either Windows Server 2008 or Windows Server 2012

installed. There are two reasons why we are using VMware Workstation in this book:

• It has fantastic documentation and support

• The image from BackTrack has the tools installed, and this makes for much

better user experience

As always, software is a matter of personal preference and taste, so try different

versions and see which one works best for you.

The procedure for starting the tool once you have downloaded the virtual machine

is pretty straightforward. Open the image in the virtual machine tool you are using

and check the settings. You should see a screen similar to the one shown in the next

screenshot. You want to check that there is a network adapter present, and that the

RAM is set to a value that you can support on your host machine. As a reminder,

2 GB of RAM is recommended. An example is shown in the next image where the

RAM is not sufficient and would need to be changed; you do this by clicking on

Edit virtual machine settings. Once you have configured this, click on Power on

this virtual machine. If you are prompted before the VM boots up, leave the default

settings, as they are and let the machine boot.

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Once the machine has booted, you will need to log in with root as the ID and a

password of toor (root in reverse). This will bring you to the shell interface of

BackTrack. We want to start up the windowing environment, but before we do that,

we want to check and verify that our network has started. Enter ifconfig; you

should see a result similar to in the next screenshot:

In some versions of the BackTrack distribution, you might not have an interface

named eth1. If you only have the lo (loopback) interface, you have to start the

network; the way to do this is by using /etc/init.d/networking start.

This will start your network.

root@bt:~# /etc/init.d/networking start

To avoid having to do this the next time you start BackTrack, enter the update-rc.d

networking defaults command. This will change the configuration, and each time

you start BackTrack, the network will be started for you.

root@bt:~# update-rc.d networking defaults

There is a possibility that when you restart, you will not get a network address;

this is rare with the latest software, but just in case, you might want to enter the

ifconfig command again.

root@bt:~# ifconfig

If you are not connected to the network, that is, if you don't have an IP address,

you can enter dhclient.

root@bt:~# dhclient

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Next, you want to start the XWindows environment; you do this by entering the

startx command in the command shell.

root@bt:~# startx

This will start the XWindows Gnome desktop. Once the window comes up, the first

thing you want to do is to open a shell on your desktop. You can accomplish this by

going to Applications | Accessories | Terminal. The next thing you want to do is to

fix your display within the virtual environment inw the VMware Workstation menu

at the top of the screen. Navigate to View | Fit Guest Now to correct the display;

your screen should now be in fullscreen mode, as shown in the following screenshot:

Next, you want to change the password from the default value of toor, which is not

a strong password. And to be honest, everyone knows it; so let us change it now. In

your command shell terminal window, enter passwd.

root@bt:~# passwd

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This will start the password change process. Enter a password of your choice; it will

not echo on the screen as you type it in, and you will be requested to re-enter your

password to confirm it. Make sure you do not forget your password, as it can be a

challenge to recover it; it is not impossible, but it is a challenge nonetheless and is

beyond the scope of this book.

As you can see from the previous screenshot, there is a transparent background

in the shell. There is a simple procedure to customize your shell, and we will do

that now. I prefer to have a white background with black text, which we will now

configure. In the title of the terminal window, navigate to Edit | Profile Preferences.

Once the window opens, you want to click on Background; this is where you will

set the transparency of the shell window. My preference is to have no transparency,

click on Transparent Background, then drag the slider to the right and set it to

Maximum as shown in the next screenshot:

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The next thing we will set is the actual colors of the terminal windows. We do this

by clicking on Colors and then setting the colors for the terminal as identified in the

following screenshot:

Once you have set the colors and transparency for the terminal, you should have

a shell with the colors that you prefer and customized in your profile, so that each

time you open a terminal window it will be configured to your preferences.

Updating BackTrack

Now that we have set up the basics on our BackTrack machine, we want to update

the tool and make sure that it is current. The developers of BackTrack have instituted

an update capability using the apt-get utility. The first thing we want to do is to

update the package. This requires a working Internet connection on your host; verify

this by opening a web browser window and accessing a website. Once you have

verified that you are connected to the Internet, go back to the BackTrack machine

and enter the apt-get update command in a terminal window.

root@bt:~# apt-get update

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Once you have entered the command, you should see a display similar to the one

shown in the next screenshot:

Once the update has finished, there should be a message saying that the update

was successful. Once the update is complete, the next thing to do is to upgrade the

distribution itself; we do that also with the apt-get command. Enter apt-get distupgrade

in the terminal window.

root@bt:~# apt-get dist-upgrade

The output of this command should be similar to the one in the following screenshot:

The output indicates the packages that are available and will be upgraded. Once

you have reviewed them, you are ready to do the upgrade; enter Y to start the

upgrade. Once the upgrade has finished, you are done with the main updates

and upgrades for BackTrack.

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Validating the interfaces

There is one more thing we want to correct when it comes to our network, because

there is a problem with the allocation of the interfaces at boot time when you make

copies of a Linux virtual machine. If you enter ifconfig and your interface does not

say eth0, you should correct the network.

root@bt:~# ifconfig

We do this by opening the configuration file and removing all references to the

network interfaces that are there. In your shell, enter gedit.

root@bt:~# gedit

This will open the graphical editor that is contained within the Gnome distribution.

In the editor, navigate to File | Open; when the window opens, navigate to the

configuration file that is located at /etc/udev/rules.d/. To navigate to the folder,

click on the File System folder in the window. This will put you in the root of the

file system; then, it is only a matter of drilling down until you get into the rules.d

folder. Select and open the 70-persistent-net.rules file. Once you are in the

file, delete the old interfaces that are there; highlight the line that starts with # PCI

Device and all the lines after that right up to the end of the file, and then delete

them as shown in the next screenshot:

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