How to crack a WEP network


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Cracking a wireless network is done for many reasons, one of which is to test the strength of the network. This is what we will be exploring. If you are reading this you should know that having your network secured by WEP is silly and you should immediately change it to WPA to prevent large amounts of stupid from spreading.

What you need:

  • Sharpie

  • At least one blank CD

    • BT3
  • Compatible computer and/or wireless adapter, you can check this here. (If your computer or adapter is not on the list give it a try anyway.)

    • bt3-compat
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  • WEP network (your own of course ;) )
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  • Imgburn, You can get this here.

    • imgburn-down
  • Backtrack image, You can get this here.

    • bt3-down

If your wireless adapter is not compatible you can get a USB one that is anyone of the following will work.


HAWKING HWU8DD USB 2.0 Hi-Gain Wireless-G Dish Adapter
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HAWKING HWUG1 USB 2.0 Wireless-G Adapter with Removable Antenna
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LINKSYS WUSB54G USB 1.1/2.0 Wireless-G Adapter
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I did all burning, downloading and anything else needed to install on a Windows 7 computer without any problems. There is no reason a XP or Vista machine won't work just as well.


Once you have all the required items, we can get started.

1. Download Backtrack3 then install ImgBurn. Once you have done this open the downloaded ISO of Backtrack in ImgBurn. It will take a few minutes to burn, once finished remove the disc and label with sharpie, for increased speed draw a picture on the top of the disc, preferably a skull and cross bones.


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imgburn
bt3-burn
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2. Insert the freshly burned disc in to the CD drive of the computer you wish to crack from.

3. Restart the computer and mash a combination of function keys until you get the boot options menu and select the disc drive containing backtrack.


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4. Select the first option from the following menu, if that one does not work right, reboot and select the next best option. It will go through a lot of text and the screen will blink a few times, if it goes dark and stays dark for more than 3 minutes restart and select a different option from the menu, if it still does not work refer to the Backtrack site.


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5. In Backtrack open the wireless manger and select your desired network to gain access to.


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6. Open SpoonWEP and enter in the settings relative to the image below.
wifi3 We used the laptop's internal wireless adapter. If the adapter of your computer is not compatible you can get a usb one that is. Select your wireless adapter (wan0 ,eth0, ath0 or something similar) you may have to open the console and bring up the adapter by typing in "ifconfig ath0( or whatever) up". If you wireless adapter is atheros based select the little check box accordingly. Adjust the channel slide until it matches the target network's channel. Drop the injection rate to zero unless you know your adapter supports it (refer to the Compatibility page).


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7. Hit Launch

It will take some time depending on the usage of the network to obtain the key.


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Once you have the key (ignore the colons) copy it to a txt file and save to a flash drive or just simply write it down.

You are all done,take the disc out and restart the computer or play with Backtrack some more. Keep the Disc with you at all times since it is extremely useful. Also keep it for future guides.

Also don't ask about WPA we will make a guide on that as soon as we develop a way that is easy enough to replicate fairly easily. Be sure to read our blog for future guides and other nonsense.

If you have any questions or require any help leave a comment on the the corresponding blog post or check out the Backtrack Forums.