Tuesday, May 8, 2012

Hacking WEP wifi passwords

1. Getting the right tools
Download Backtrack 3. It can be found here:
The Backtrack 4 beta is out but until it is fully tested (especially if you are a noob) I
would get the BT3 setup. The rest of this guide will proceed assuming you downloaded
BT3. I downloaded the CD iso and burned it to a cd. Insert your BT3 cd/usb drive and
reboot your computer into BT3. I always load into the 3rd boot option from the boot
menu. (VESA/KDE) You only have a few seconds before it auto-boots into the 1st
option so be ready. The 1st option boots too slowly or not at all so always boot from
the 2nd or 3rd. Experiment to see what works best for you.

2. Preparing the victim network for attack
Once in BT3, click the tiny black box in the lower left corner to load up a "Konsole"
window. Now we must prep your wireless card.


You will see the name of your wireless card. (mine is named "ath0") From here on out,
replace "ath0" with the name of your card.
Now type:
airmon-ng stop ath0

then type:
ifconfig wifi0 down
macchanger --mac 00:11:22:33:44:55 wifi0
airmon-ng start wifi0

What these steps did was to spoof (fake) your mac address so that JUST IN CASE
your computeris discovered by someone as you are breaking in, they will not see your
REAL mac address. Moving on...
Now it's time to discover some networks to break into.


airodump-ng ath0
Now you will see a list of wireless networks start to populate. Some will have a better
signal than others and it is a good idea to pick one that has a decent signal otherwise
it will take forever to crack or you may not be able to crack it at all.
Once you see the network that you want to crack, do this:

hold down ctrl and tap c
This will stop airodump from populating networks and will freeze the screen so that
you can see the info that you need.

**Now from here on out, when I tell you to type a command, you need to replace
whatever is in parenthesis with what I tell you to from your screen. For example: if i
say to type:
-c (channel)
then dont actually type in
-c (channel)
Instead, replace that with whatever the channel number is...so, for example you would
-c 6
Can't be much clearer than that...lets continue...

Now find the network that you want to crack and MAKE SURE that it says the
encryption for that network is WEP. If it says WPA or any variation of WPA then
move on...you can still crack WPA with backtrack and some other tools but it is a
whole other ball game and you need to master WEP first. 

Once you've decided on a network, take note of its channel number and bssid. The
bssid will look something like this --> 05:gk:30:fo:s9:2n
The Channel number will be under a heading that says "CH".
Now, in the same Konsole window, type:

airodump-ng -c (channel) -w (file name) --bssid (bssid) ath0

the FILE NAME can be whatever you want. This is simply the place that airodump is
going to store the packets of info that you receive to later crack. You don't even put
in an extension...just pick a random word that you will remember. I usually make mine
"wepkey" because I can always remember it.

**Side Note: if you crack more than one network in the same session, you must have
different file names for each one or it won't work. I usually just name them wepkey1,
wepkey2, etc.

Once you typed in that last command, the screen of airodump will change and start to
show your computer gathering packets. You will also see a heading marked "IV" with a
number underneath it. This stands for "Initialization Vector" but in noob terms all
this means is "packets of info that contain clues to the password." Once you gain a
minimum of 5,000 of these IV's, you can try to crack the password.

I've cracked some right at 5,000 and others have taken over 60,000. It just depends
on how long and difficult they made the password. 

Now you are thinking, "I'm screwed because my IV's are going up really slowly." Well,
don't worry, now we are going to trick the router into giving us HUNDREDS of IV's
per second. 

3. Actually cracking the WEP password

Now leave this Konsole window up and running and open up a 2nd Konsole window. In
this one type

aireplay-ng -1 0 -a (bssid) -h 00:11:22:33:44:55 ath0

This will generate a bunch of text and then you will see a line where your computer is
gathering a bunch of packets and waiting on ARP and ACK. Don't worry about what
these mean...just know that these are your meal tickets. Now you just sit and wait.
Once your computer finally gathers an ARP request, it will send it back to the router
and begin to generate hundreds of ARP and ACK per second. Sometimes this starts to
happen within seconds...sometimes you have to wait up to a few minutes. Just be
patient. When it finally does happen, switch back to your first Konsole window and
you should see the number underneath the IV starting to rise rapidly. This is great!
It means you are almost finished! When this number reaches AT LEAST 5,000 then
you can start your password crack. It will probably take more than this but I always
start my password cracking at 5,000 just in case they have a really weak password.

Now you need to open up a 3rd and final Konsole window. This will be where we
actually crack the password. Type:

aircrack-ng -b (bssid) (filename)-01.cap

Remember the filename you made up earlier? Mine was "wepkey". Don't put a space in
between it and -01.cap here. Type it as you see it. So for me, I would type
Once you have done this you will see aircrack fire up and begin to crack the password.
typically you have to wait for more like 10,000 to 20,000 IV's before it will crack. If
this is the case, aircrack will test what you've got so far and then it will say
something like "not enough IV's. Retry at 10,000." DON'T DO ANYTHING! It will
stay running...it is just letting you know that it is on pause until more IV's are
gathered. Once you pass the 10,000 mark it will automatically fire up again and try to
crack it. If this fails it will say "not enough IV's. Retry at 15,000." and so on until it
finally gets it. 

If you do everything correctly up to this point, before too long you will have the
password! now if the password looks goofy, dont worry, it will still work. some
passwords are saved in ASCII format, in which case, aircrack will show you exactly
what characters they typed in for their password. Sometimes, though, the password
is saved in HEX format in which case the computer will show you the HEX encryption
of the password. It doesn't matter either way, because you can type in either one
and it will connect you to the network. 

Take note, though, that the password will always be displayed in aircrack with a colon
after every 2 characters. So for instance if the password was "secret", it would be
displayed as:
This would obviously be the ASCII format. If it was a HEX encrypted password that
was something like "0FKW9427VF" then it would still display as:
Just omit the colons from the password, boot back into whatever operating system
you use, try to connect to the network and type in the password without the colons
and presto! You are in!

It may seem like a lot to deal with if you have never done it, but after a few
successful attempts, you will get very quick with it. If I am near a WEP encrypted
router with a good signal, I can often crack the password in just a couple of minutes. 

I am not responsible for what you do with this information. Any malicious/illegal
activity that you do, falls completely on you because...technically...this is just for you
to test the security of your own network. :-)

I will gladly answer any legitimate questions anyone has to the best of my ability.
ANSWERED. No one wants to hold your hand through this...read the tut and go
experiment until you get it right.

There are rare occasions where someone will use WEP encryption with SKA as well.
(Shared Key Authentication) If this is the case, additional steps are needed to
associate with the router and therefore, the steps I lined out here will not work. I've
only seen this once or twice, though, so you probably won't run into it. If I get
motivated, I may throw up a tut on how to crack this in the future. 


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