Hacking Wi-Fi Networks with Fern, Kali and a Raspberry Pi

Fern Wifi Cracker 1

Wouldn’t it be cool to be able to test wireless network security using your Raspberry Pi? Well, thanks to Kali Linux, you can! With Kali you can scan for Wi-Fi networks and even perform active penetration testing using your $35 Raspberry Pi.

I just finished up another article for Hakin9 Magazine. In the article I covered using a Raspberry Pi to crack Wi-Fi security from install to basic pentesting.

With Kali you can use all the normal command line airmon-ng tools that you can use on a regular Linux machine. Fern is nice because it adds a graphical interface to the airmon-ng tools making things so much easier.

Let’s take a quick look at Fern:

(NOTE: As always, these techniques are for IT teams and computer security testers, never attack or attempt to access a network that you do not own or have permission to access.)

From the main menu (see picture above) just select your wireless card, then scan for access points. As they are found Fern lists them under the WEP or WPA Button.

Fern Wifi Cracker Detected

Clicking the associated button will display a list of the access points found. Then just select the one you want to test. You now have two attack options. You can select the Reaver WiFi Protected Setup (WPS) attack and a normal Association Key dictionary brute force attack :

Fern Wifi Cracker Detected 2

Fern works very well and is actually pretty responsive when run on a Raspberry Pi.

With the Pi being so small and cheap, this opens up some interesting options for professional penetration testers, especially when paired with a USB Wi-Fi adapter and a battery back.

For a lot more information on computer security, including bypassing the most common Wi-Fi security techniques, check out my new step-by-step tutorial book, “Basic Security Testing with Kali Linux”.


6 thoughts on “Hacking Wi-Fi Networks with Fern, Kali and a Raspberry Pi”

  1. Hi, I am kind of new for using Linux but I was impressed with seeing kali Linux. My lap top is Lenovo G570 and it has WiFi internal card: Broadcom 802.11n card . So I installed VMware workstation 9 in my lap top and also kali Linux so that I can run it under VM. all installation went through, I can open Fern Wifi Craker but it does not show up the wireless card. I tried a few things but it did not work at all, your comment would be appreciated.

    1. At a terminal prompt, type in “ifconfig” and see if a wlan0 interface is listed. If not, type “ifconfig wlan0 up” and then type ifconfig again to see if it sees it now. If not, it could be a driver issues.

      1. Hi, thanks for your reply,
        ifconfig shows me the eth0 and lo which I know eth0 works and I can internet connection through wired net. when I type iwconfig there will not be seen any wifi lan( lo no wireless extensions eth0 no wireless extensions. when I type ifconfig wlan0 up the error message:
        wlan0: ERROR while getting interface flags: No such device
        so, any recommendation for installing driver into kali? wifi card is brcm and I checked the lib/firmware of kali and it includes bcm43xx driver plus bcm2033. do you recommand any other driver?thanks

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