Book Image

Applied Network Security

By : Arthur Salmon, Michael McLafferty, Warun Levesque
Book Image

Applied Network Security

By: Arthur Salmon, Michael McLafferty, Warun Levesque

Overview of this book

Computer networks are increasing at an exponential rate and the most challenging factor organisations are currently facing is network security. Breaching a network is not considered an ingenious effort anymore, so it is very important to gain expertise in securing your network. The book begins by showing you how to identify malicious network behaviour and improve your wireless security. We will teach you what network sniffing is, the various tools associated with it, and how to scan for vulnerable wireless networks. Then we’ll show you how attackers hide the payloads and bypass the victim’s antivirus. Furthermore, we’ll teach you how to spoof IP / MAC address and perform an SQL injection attack and prevent it on your website. We will create an evil twin and demonstrate how to intercept network traffic. Later, you will get familiar with Shodan and Intrusion Detection and will explore the features and tools associated with it. Toward the end, we cover tools such as Yardstick, Ubertooth, Wifi Pineapple, and Alfa used for wireless penetration testing and auditing. This book will show the tools and platform to ethically hack your own network whether it is for your business or for your personal home Wi-Fi.
Table of Contents (18 chapters)

The Transmission Control Protocol (TCP) handshake

Also known as a three-way handshake, this requires the two hosts to be synchronized with each other's initial sequence number (ISN) for a connection to be established, before data transfer begins. The need for us to obtain a TCP handshake is because the hash (a hash is a string or number generated from a string of plain text) is stored within the SYN/ACK packet:

  1. You can use the following command to send a deauthentication to the AP: aireplay-ng --deauth 10 -a 02:13:37:A5:99:E3 -c 10:03:cd:04:06:fe wlan0mon:
  • --deauth 10 means sending 10 packets to deauthenticate that device
  • -a is the target device (your Wi-Fi router)
  • -c is the connected station (connected device on the network):
  1. You're doing this to recapture the TCP handshake, which will be saved in your CrackWPA file:
  1. Now clean it of any unneeded data, and convert it to run with hashcat: