Question

- Do this lab using kali machine

1) Add an admin level user in the system

2) Show which users are logged into a system.

3) Check the listening network ports on your system.   

4) Install and setup Secure Shell service on your system, and test it.   

5) Check Password Expiration of User.   

6) Keep /boot as read-only.

7) Display all the users present in the system.

8) Print on screen the linux file that contains the passwords for all users.

Answer 1

1. Add an admin level user in the system

• Login as root
• Open terminal and type the below command to create a new user:
• "useradd -m username".
• Click on enter(return).
• Once a user has been created, a new password should also been provided.
• To create a new passport, type in the command: "passwd" followed by the username.
• Enter the new password in the prompt.
• Retype the same password.
• To make the account as administrator account who can have access to other accounts, type the command " usermod -a -G sudo username"
• Then type in the command chsh -s /bin/bash username to make this change.

2. Show which users are logged into a system.

"w" is the command to print the names of all the logged-on users. However, "whoami" is the command used to print the list of effective user-id who are currently logged in.
3. Check the listening network ports on your system.

"sudo netstat -ltup " command prints all the listening sockets on the system.
In this command, -l prints all listening sockets.
-t prints all the TCP connections.
-u prints all the UDP connections.
-p is used to prints the application name listening on the port.
4. Install and setup Secure Shell service on your system, and test it.

To install SSH (secure shell) please follow the below steps:
Open terminal and type in the command:
"apt -get update"
Followed by the command:
" apt -get install ssh"

To set up the secure shell type the command:
"systemctl enable ssh".
This command enables SSH to start after it has been rebooted.

To test start SSH for a current session type the command:
"service SSH start".

5. Check Password Expiration of User

"chage -l username" commands displays the password details such as the created date and expiry date on most of the Linux system

Note: please remove all the double quotes before entering the commands.

Thankyou