1. Which type of tool is used by a Linux administrator to attack a computer or network to find vulnerabilities?
- intrusion detection system
- malware analysis
- PenTesting
- firewall
Explanation: PenTesting is known as penetration testing and includes tools that are used to search for vulnerabilities in a network or computer by attacking it.
2. What is a benefit of Linux being an open source operating system?
- Linux distribution source code can be modified and then recompiled.
- Linux distributions are maintained by a single organization.
- Linux distributions must include free support without cost.
- Linux distributions are simpler operating systems since they are not designed to be connected to a network.
Explanation: Linux is an open source operating system and any person can access the source code, inspect it, modify it, and recompile it. Linux distributions are maintained by a community of programmers and are designed to be connected to a network and do not have to provide free support.
3. Which method can be used to harden a device?
- Allow USB auto-detection.
- Force periodic password changes.
- Allow users to re-use old passwords.
- Allow default services to remain enabled.
Explanation: The basic best practices for device hardening are as follows:
- Ensure physical security.
- Minimize installed packages.
- Disable unused services.
- Use SSH and disable the root account login over SSH.
- Keep the system updated.
- Disable USB auto-detection.
- Enforce strong passwords.
- Force periodic password changes.
- Keep users from re-using old passwords.
- Review logs regularly.
4. A system administrator issues the command ps on a server that is running the Linux operating system. What is the purpose of this command?
- to list the processes currently running in the system
- to display the contents of the current directory
- to process a new task
- to change file permissions
Explanation: The Linux ps command is used to list the currently running processes in the system. If needed, this command can be instructed to display running processes initiated by the current user or other users.
5. Which operating system source code can be downloaded and modified by any person or company?
- Cisco IOS
- Mac OS X
- Linux
- Windows
Explanation: Open-source programs, like Linux, allow the source code to be distributed and changed by anyone.
6. Which file system is the primary file system used by Apple in current Macintosh computers?
- CDFS
- APFS
- ext3
- ext2
- HFS+
Explanation: The primary file system used by Apple in its lates Macintosh computers is APFS.
7. Consider the result of the ls -l command in the Linux output below. What are the group file permissions assigned to the analyst.txt file?
ls –l analyst.txt -rwxrw-r-- sales staff 1028 May 28 15:50 analyst.txt
- read, write, execute
- read only
- read, write
- full access
Explanation: The file permissions are always displayed in the User, Group and Other order. In the example displayed, the file has the following permissions:
- The dash (–) means that this is a file. For directories, the first dash would be replaced with a \”d\”.
- The first set of characters is for user permission (rwx). The user, sales, who owns the file can read, write and execute the file.
- The second set of characters is for group permissions (rw–). The group, staff, who owns the file can read and write to the file.
- The third set of characters is for any other user or group permissions (r–). Any other user or group on the computer can only read the file.
8. In the context of a Linux operating system, which command can be used to display the syntax and parameters for a specific command?
- crontab
- man
- grep
- cat
Explanation: The functions of listed CLI commands of a Linux system are as follows:
- cat – lists the contents of a file
- man – displays the documentation for a specific command
- crontab – manages the cron service for scheduling system tasks
- grep – searches for specific strings of characters within a file or other commands outputs
9. What is a daemon?
- a type of security attack
- a background process that runs without the need for user interaction
- a record to keep track of important events
- an application that monitors and analyzes suspicious activity
Explanation: A daemon in Linux is a background process that runs without the need for user interaction. A network administrator can view log files in order to see information about daemons running on the Linux server.
10. Which Linux command can be used to display the name of the current working directory?
- sudo
- pwd
- chmod
- ps
Explanation: One of the most important commands in Linux is the pwd command, which stands for print working directory. It shows users the physical path for the directory they are working in.
11. An author is uploading one chapter document from a personal computer to a file server of a book publisher. What role is the personal computer assuming in this network model?
- client
- secondary
- server
- primary
- transient
Explanation: In the client/server network model, a network device assumes the role of server in order to provide a particular service such as file transfer and storage. The device requesting the service assumes the role of client. In the client/server network model, a dedicated server does not have to be used, but if one is present, the network model being used is the client/server model. In contrast, the peer-to-peer network model does not have a dedicated server.
12. A technician has captured packets on a network that has been running slowly when accessing the internet. Which port number should the technician look for within the captured material to locate HTTP packets?
- 21
- 20
- 110
- 53
- 80
Explanation: HTTP uses TCP port 80 and HTTPS uses TCP port 443. HTTP and HTTPS are protocols commonly used to access web pages.
13. A system administrator issues the apt-get upgrade command on a Linux operating system. What is the purpose of this command?
- The remote repository of applications and dependencies will be updated to the latest version.
- A specific application named upgrade will be installed.
- Operating system updates are downloaded and will be installed.
- Every application installed will update itself to the latest version.
Explanation: When the apt-get upgrade command is issued in a Linux terminal, all installed applications will attempt to upgrade to the latest version available.
14. Why would a rootkit be used by a hacker?
- to reverse engineer binary files
- to do reconnaissance
- to try to guess a password
- to gain access to a device without being detected
Explanation: Hackers use rootkits to avoid detection as well as hide any software installed by the hacker.