INTRODUCTION TO KALI LINUX

A brief history of Kali Linux

Kali Linux (Kali) is a Linux distribution system that was developed with a focus on
the penetration testing task. Previously, Kali Linux was known as BackTrack, which
itself is a merger between three different live Linux penetration testing distributions:
IWHAX, WHOPPIX, and Auditor.
BackTrack is one of the most famous Linux distribution systems, as can be proven by
the number of downloads that reached more than four million as of BackTrack Linux
4.0 pre final.
Kali Linux Version 1.0 was released on March 12, 2013. Five days later, Version 1.0.1
was released, which fixed the USB keyboard issue. In those five days, Kali has been
downloaded more than 90,000 times.

The following are the major features of Kali Linux

• It is based on the Debian Linux distribution
• It has more than 300 penetration testing applications
• It has vast wireless card support
• It has a custom kernel patched for packet injection
• All Kali software packages are GPG signed by each developer
• Users can customize Kali Linux to suit their needs
• It supports ARM-based systems

Kali Linux tool categories

Kali Linux contains a number of tools that can be used during the penetration testing
process. The penetration testing tools included in Kali Linux can be categorized into
the following categories:

• Information gathering: This category contains several tools that can be
used to gather information about DNS, IDS/IPS, network scanning,
operating systems, routing, SSL, SMB, VPN, voice over IP, SNMP, e-mail
addresses, and VPN.

• Vulnerability assessment: In this category, you can find tools to scan
vulnerabilities in general. It also contains tools to assess the Cisco network,
and tools to assess vulnerability in several database servers. This category
also includes several fuzzing tools.

• Web applications: This category contains tools related to web applications
such as the content management system scanner, database exploitation,
web application fuzzers, web application proxies, web crawlers, and web
vulnerability scanners.

• Password attacks: In this category, you will find several tools that can be
used to perform password attacks, online or offline.

• Exploitation tools: This category contains tools that can be used to exploit
the vulnerabilities found in the target environment. You can find exploitation
tools for the network, Web, and database. There are also tools to perform
social engineering attacks and find out about the exploit information.

• Sniffing and spoofing: Tools in this category can be used to sniff the network
and web traffic. This category also includes network spoofing tools such as
Ettercap and Yersinia.

• Maintaining access: Tools in this category will be able to help you maintain
access to the target machine. You might need to get the highest privilege
level in the machine before you can install tools in this category. Here, you
can find tools for backdooring the operating system and web application.
You can also find tools for tunneling.

• Reporting tools: In this category, you will find tools that help you document
the penetration-testing process and results.

• System services: This category contains several services that can be useful
during the penetration testing task, such as the Apache service, MySQL
service, SSH service, and Metasploit service.

To ease the life of a penetration tester, Kali Linux has provided us with a category
called Top 10 Security Tools. Based on its name, these are the top 10 security
tools commonly used by penetration testers. The tools included in this category
are aircrack-ng, burp-suite, hydra, john, maltego, metasploit, nmap, sqlmap,
wireshark, and zaproxy.

Besides containing tools that can be used for the penetration testing task, Kali Linux
also comes with several tools that you can use for the following:

• Wireless attacks: This category includes tools to attack Bluetooth, RFID/
NFC, and wireless devices.

• Reverse engineering: This category contains tools that can be used to debug
a program or disassemble an executable file.

• Stress testing: This category contains tools that can be used to help you in
stress testing your network, wireless, Web, and VOIP environment.

• Hardware hacking: Tools in this category can be used if you want to work
with Android and Arduino applications.

• Forensics: In this category, you will find several tools that can be used for
digital forensics, such as acquiring a hard disk image, carving files, and
analyzing the hard disk image. To use the forensics capabilities in Kali Linux
properly, you need to navigate to Kali Linux Forensics | No Drives or Swap
Mount in the booting menu. With this option, Kali Linux will not mount the
drives automatically, so it will preserve the drives' integrity.
In this book, we are focusing only on Kali Linux's penetration testing tools.