Linux is an open-source operating system that provides various utilities that help professionals to perform their tasks in an efficient and simple way. Linux has been known in the industry as one of the most stable operating systems. Linux OS provides a useful set of preinstalled utilities that allows the user to perform the required tasks easily, it also provides multiple applications and packages that can be installed to be used for different purposes. Using these utilities without limitations and restrictions would allow many of the breakthroughs that can be prevented by applying simple security standards. Securing a Linux machine is an important task and the security issue becomes one of the main priorities when dealing with the machine as a server. Security should be one of the first considerations at all stages of setting up a Linux computer. Securing a Linux machine is a primary responsibility and maintaining a secure environment becomes one of the main priorities when dealing with Log files. This book presents a detailed practical step by step guide to experiment and master Linux security-related tools.
Author(s): Musaab Hasan & Zayed Balbahaith
Edition: 1
Publisher: Lambert Academic Publishing
Year: 2020
Language: English
Pages: 125
Chapter I: Getting Started With Linux OS ..................................................................................... 3
Chapter Objectives ....................................................................................................................................... 4
Needed Tools ............................................................................................................................................... 4
Chapter Overview......................................................................................................................................... 4
Basic Linux Commands ................................................................................................................................. 5
Creating and Removing Directories............................................................................................................ 12
Output Redirection..................................................................................................................................... 15
Manipulating Files ...................................................................................................................................... 18
Running and managing processes in the background ................................................................................ 25
Becoming a super-user............................................................................................................................... 28
Using ssh to connect to another machine.................................................................................................. 32
Using VirtualBox and Kali Linux .................................................................................................................. 34
Examining Further Linux Commands.......................................................................................................... 35
End of Chapter Conclusions & Recommendations ..................................................................................... 50
Chapter II: Exploring Various Security Tools ............................................................................... 52
Chapter Objectives ..................................................................................................................................... 53
Needed Tools ............................................................................................................................................. 53
Chapter Overview....................................................................................................................................... 53
Tasks & Procedures .................................................................................................................................... 54
Default File Permissions ............................................................................................................................. 55
Password files............................................................................................................................................. 57
Sudo ........................................................................................................................................................... 58
Installing Software Packages (RPM and YUM) ........................................................................................... 62
Console and Login Security ........................................................................................................................ 65
Wireshark ................................................................................................................................................... 71
End of Chapter Conclusions & Recommendations ..................................................................................... 75
Chapter III Digging Deeper into Linux ........................................................................................ 76
Chapter Objectives ..................................................................................................................................... 77
Needed Tools ............................................................................................................................................. 77
Chapter Overview....................................................................................................................................... 77
SUID and SGID ............................................................................................................................................ 78
SUID Vulnerability ...................................................................................................................................... 82
Firewall ....................................................................................................................................................... 85
Immutable Files .......................................................................................................................................... 87
Forwarding X with OpenSSH ...................................................................................................................... 89
Managing Files............................................................................................................................................ 91
Mounting the File System and NFS ............................................................................................................ 93
End of Chapter Conclusions & Recommendations ..................................................................................... 97
Chapter IV Advanced Linux Tools ............................................................................................... 98
Chapter Objectives ..................................................................................................................................... 99
Needed Tools ............................................................................................................................................. 99
Chapter Overview....................................................................................................................................... 99
Syslog Basics ............................................................................................................................................. 100
Fine Tuning the Defaults .......................................................................................................................... 103
Dmesg....................................................................................................................................................... 104
Log Rotation ............................................................................................................................................. 105
Apache HTTP or Tomcat ........................................................................................................................... 108
Listing Open Files...................................................................................................................................... 109
Cracking the system through boot loader ................................................................................................ 111
File Integrity Check with TripWire ............................................................................................................ 115
Syslog-ng .................................................................................................................................................. 115
End of Chapter Conclusions & Recommendations ................................................................................... 116
