Linux: Linux Security and Administration

109 Pages·2021·1.841 MB·English

by  Andy Vickler

Linux
Linux Security and Administration
© Copyright 2021 - All rights reserved.
The contents of this book may not be reproduced, duplicated or transmitted without direct written
permission from the author.
Under no circumstances will any legal responsibility or blame be held against the publisher for any
reparation, damages, or monetary loss due to the information herein, either directly or indirectly.
Legal Notice:
This book is copyright protected. This is only for personal use. You cannot amend, distribute, sell, use,
quote or paraphrase any part or the content within this book without the consent of the author.
Disclaimer Notice:
Please note the information contained within this document is for educational and entertainment
purposes only. Every attempt has been made to provide accurate, up to date and reliable complete
information. No warranties of any kind are expressed or implied. Readers acknowledge that the author
is not engaging in the rendering of legal, financial, medical or professional advice. The content of this
book has been derived from various sources. Please consult a licensed professional before attempting
any techniques outlined in this book.
By reading this document, the reader agrees that under no circumstances is the author responsible for
any losses, direct or indirect, which are incurred as a result of the use of information contained within
this document, including, but not limited to, —errors, omissions, or inaccuracies.
Table of Contents
Introduction
Chapter One: Using Linux on Virtual Machines
Installing a Workstation Player
Choose the Correct Distro
Linux Distros
Setting Up the Virtual Machine
Customizing Virtual Hardware
Download and Install Tools
Installing Linux on VMware
Running Linux on a Virtual Machine
Installing a Linux Distro on a Windows Virtual Machine
Chapter Two: Securing User Accounts on Linux
Don’t Login Using a Root Account
Using Sudo Accounts
Reducing the Damage
Fine-Grained Permissions
Managing User Account Security
Adding New Users
Disable Root Login
Password Policies in Linux
Restrict SSH Access
Understanding Account Privileges
Manage Linux User Accounts
Reducing Privileges
Managing Passwords
Reduce the Use of Shared Accounts
Control Access to Accounts
Maintain Logs
Record and Manage Privileged Activity
Notify or Alert in Case of Suspicious Activity
Unify and Centralize
Chapter Three: Securing Servers Using Firewalls
Ports
Using the Firewall-cmd Interface
Bock Everything
Creating a Zone
Removing or Adding Services
Unblocking a Service
Removing and Adding Ports
Walls of Fire
Chapter Four: Securing Your Server
Updating Servers Regularly
Creating a Secondary User Account
Setting up SSH Keys
Checking and Configuring the Firewall
Limiting the Use of Open Ports
Setting Up Live Kernel Patches
Hardening the Kernel
Hardening User Space
Using Secure Boot
Setting Up Two-Factor Authentication
Step One
Step Two
Step Three
Step Four
Step Five
Turning Off Internet Protocols
Understanding the Applications/Tools before Installation
Removing Unnecessary Startup Processes
Reviewing Activities Regularly
Start Backing Up
Only Install the Things You Need
Use SELinux
Securing the Console Access
Restricting the Use of Old Passwords
Checking Listening Ports
Disabling Login through the Root
Change Ports
Disabling Shortcuts
Logging In Without Passwords
Use fail2ban
Creating a New Privileged Account
Uploading the SSH Key
Securing SSH
Creating a Firewall
Removing Unused Network Services
Chapter Five: Password Encryption Methods in Linux
Pretty Good Privacy (PGP) and Public-Key Cryptography
S/MIME, SSL and S-HTTP
S/MIME
SSL
S-HTTP
Linux IPSEC Implementation
Secure Telnet (stelnet) and Secure Shell (ssh)
Pluggable Authentication Modules or PAM
CIPE or Cryptographic IP Encapsulation
Using Shadow Passwords
John the Ripper and Crack
Chapter Six: Tools to Encrypt and Decrypt Password Protected Files
GNU Privacy Guard or GnuPG
Bcrypt
Ccrypt
4-Zip
Openssl
7-Zip
Nautilus Encryption Utility
Encryption
Decryption
Chapter Seven: Using Tools to Encrypt Files on Linux
Tomb
Cryptmount
CryFS
GnuPG
VeraCrypt
EncFS
7-zip
Dm-crypt
eCryptfs
Cryptsetup
Chapter Eight: Using Cryptsetup to Setup Encrypted Filesystems and
Swap Space
Using a Drive, Loop Device, or Partition for Encryption
Testing the Encryption
Installing cryptsetup
Setting the Encrypted Partition
Testing Encryption
Adding Additional Layers of Security
Chapter Nine: Using Access Control Lists in Linux
Introduction to Access Control Lists (ACL)
Uses of ACL
List of Commands to Set Up ACLs
Adding Permissions to Users
Adding Permissions to Groups
Allowing Files and Directories to Inherit ACL Entries
Removing a Specific Entry in the ACL
Removing Entries in ACL
Modifying the ACL
Adding Permissions for Users
Adding Permissions to Groups
Allow Files or Directories to Inherit the ACL Entries
Viewing ACL
Removing ACL
Using Default ACLs
Chapter Ten: Downloading and Installing Kali Linux
Downloading Kali Linux
Hard Disk Installation
Booting Kali Linux for the First Time
Setting the Defaults
Initial Network Setup
Password
System Clock
Disk Partitioning
Configuring the Packet Manager
Installing the GRUB Loader
Completing the Installation
USB Drive Installation
Windows Non-Persistent Installation
Linux Persistent Installation
Chapter Eleven: The Penetration Testing Life Cycle
The Five Stages of the Penetration Testing Life Cycle
Stage 1: Reconnaissance
Stage 2: Scanning
Stage 3: Exploitation
Stage 4: Maintaining Access
Stage 5: Reporting
Chapter Twelve: Scanning
Network Traffic
Firewalls and Ports
PING
Traceroute
Nmap: The King of Scanners
Conclusion
References
Introduction
If you are new to using Linux, it will be difficult for you to find the right
information online. This book has all the information you need to help you
install the operating system and show you how you can use it either on your
system or a virtual system. The book also has information about how you
need to configure user access and other information to maintain the network
and server's security on the Linux system. You do not have to know anything
about Linux before you use it since the information in this book will guide
you every step of the way!
The book introduces the idea of using Linux on a virtual system and provides
information on the different distributions of Linux. You can use this
information to determine which distros work best for you and download that
onto your system. You will also learn about the importance of a root account
and the other accounts on the server. The book also provides information
about the methods used to control access to users. You will learn how you
can grant and revoke privileges to users to help you protect the data.
The book covers how you can secure the information, files, and folders in the
operating system. You will be introduced to a list of tools you can use to
secure the data on your systems and how you can encrypt and decrypt
information using these tools. You can also use passwords to encrypt and
decrypt the files and folders on the server and network if you need to.
Since Linux is an operating system, and the data is stored on a server or
network, you need to test the network and server's strength. This book will
shed light on the method you can use to identify any vulnerability in the
system. It will also let you know how you can use scanning to identify the
holes in your system. You can use the information in this book to determine
how to overcome those vulnerabilities.
Thank you for purchasing the book. I hope you learn more about Linux and
how you can protect the information in your files and folders.