CYSE 270 – Linux Systems for Cybersecurity

Reflection • Assignment 1 – Creating a Kali Linux VM & Command Practice

I was able to build a Kali Linux virtual machine in Oracle VirtualBox using an understanding of the various parts of virtual machines. Also, I learned some basic command line instructions to be used within the virtual machine. I learned how to install the virtual machine through UTM and chose Ubuntu as my OS. The biggest challenge I faced during my work, though, was properly configuring my virtual machine. The good part is I was able to troubleshoot and work through those issues. One of my next steps was to verify the use of terminal commands by testing the echo, date, ls, and pwd commands. My terminal command line navigation skills started with these testing steps, and I’ve established a strong base for learning Linux and virtual machines. Learning Linux and virtual machines are both critical elements in the field of cyber security.

Reflection • Assignment 2 – Linux File Navigation & Management

I’ve experienced development through completing this assignment. I used the terminal-based interfaces within LGNU, I was able to gain proficiency using terminal commands as well as creating directories. I learned how to create and delete files/directories. Initially, there were a few commands which proved challenging for me to execute, however I eventually gained enough experience where I felt more comfortable performing these tasks. In the end my confidence with Linux has grown through my use of this software.

Reflection • Lab 3 – VI Editor

The vi editor in Linux and how to use the various modes of it was the main focus of this lab. In addition to learning the commands used to create and manipulate files. I also gained experience with how vi works. Initially, I found moving around and editing files within vi to be much more difficult than with a typical text editor because of the way vi operates. Remembering to switch between insert and command mode was initially difficult; however, the learning curve decreased with each lesson as I developed the ability to keep the key functions contained by using the escape key. As I became more proficient, I became more confident in my ability to use commands to edit files efficiently. Overall, this labs’ successful outcomes will assist me in being able to better use the vi editor as one of the key tools utilized within Linux when completing cybersecurity tasks, as well as other tasks.

Reflection • Lab 4 – User and Group Accounts

From this lab, I learned how to manage users and groups in Linux. I learned how to create user accounts, set passwords, assign shells, and add users to different groups such as sudo. I also learned how to create groups and to modify groups by assigning group ownership to files that I created. There were parts that were difficult for me, especially remembering which command and option were necessary when working with users and groups, but I got better at doing account management tasks after following the steps and practicing. Overall, by completing this lab, I now have actual experience with user and group administration, which is a very useful skill for system administrators and cybersecurity professionals.

Reflection • Lab 5 – Password Cracking

The lab was an introduction to password strength and the methods that are used to crack various types of passwords. I had to create a number of users with different complexities of passwords which helped me to understand how much more vulnerable weaker passwords are than stronger ones. Before I participated in this lab, I had never used the program John the Ripper, so I learned how to perform a password hash against a word list (rockyou.txt). One challenge that I faced when I was using this tool was figuring out how to set up and run the tool properly; once I figured out how to do that, I was able to see how quickly some of the simpler passwords were cracked. Overall the lab allowed me to understand the importance of having strong, complex passwords and provided insight into the exploits that attackers will use to compromise weak credentials in the field of cybersecurity.

Reflection • Lab 6 – User, Group, and Permission Management Lab

Through this lab, I learned how to control and manage users & groups as well as set file access permissions on Linux. I had created users/groups with primary and secondary allocations while additionally having created a Shared Folder with assigned File Access Permissions to test. The use of umask for the previously mentioned creation of Users/Groups/File Access Permissions was new to me. Working with SGID and the benefits of many Users Being Able to Maintain Their Own Group Permissions on Shared Directories provided Me with an Incredible Experience when Implementing User Access Control In Linux. Access Control Is One Of The Most Significant Aspects Of Cybersecurity, Which Is Why Protecting Files & Managing User Privileges Is So Important In Cybersecurity.

Lab 7 – Manage Local Storage

Your overview does an excellent job of illustrating the change from relying on expert judgment for ranking vulnerabilities to making those rankings data driven by using actual attacks to determine which vulnerabilities were frequently exploited in the real world. Additionally, it clearly shows why some of the vulnerabilities that consistently rise to the top will continue to be seen in active attacks due to the very detrimental effects they can have on system integrity, confidentiality, and availability (i.e., poor input validation, XSS, and buffer overflows).

Lab 8 – Shell Scripting

I was introduced to basic shell scripting on the Linux OS as part of this lab utilizing editors such as vi and nano. I learned how to create a script with the shebang #!/bin/bash , assign its permission to be executed using the chmod +x command in the terminal, then run the created script from the terminal. The first task (Task A) was to write a script that reads a number and checks if that number is greater than 10. The second task (Task B) was to write a script that checks whether a given input is either a directory or regular file and if it exists, outputs the contents of that file. If the file doesn’t exist, it will create that file. The extra credit portion allowed me to practice validating directories and displaying their contents. I did struggle to remember correct syntax for the conditional statements and the syntax for checking files, but I found that practicing through writing scripts helped me learn how to automate tasks through the use of scripts. In summary, this lab worked as a foundation for me on basic shell scripting; therefore, it will be useful to me in both automation as well as system administration.

Assignment-9

This lab has helped me learn how to use shell scripting and bash to automate the backup of a system on a Linux machine using crontab. I began by creating a new user with the appropriate privileges and then developed a shell script that would create a backup of that user’s home directory using the tar command. I also used a variable for my MIDAS name and another variable for the date in order to create a unique name for each backup. After the script was created, I moved the backup file to the /var/backups directory and compressed it to save disk space. One of the challenges included working with the permissions associated with the /var/backups directory. Overall, the lab taught me about automation/scheduling/efficient backup management on Linux.

Lab 11 – Basic Network Configurations

During the lab experiment, I learned how to set up Linux networks with commands such as IEI and using tools like netstat and ping. When testing NAT connections, I found the IP address of the NAT, looked at the routing tables, set the DNS settings, and tested connectivity with the NAT and system as well as changing the system hostname. I then switched to bridging and repeated the steps that were taken to test the network connection in NAT Mode. I observed the differences between Bridge and NAT connections: the NAT created a different IP address for the system and gave the NAT direct access to the Network.