The 5-tuple approach consists of protocol, source IP address, source port number, destination IP address, and destination port number to uniquely identify sessions between endpoints on a network. References := Cisco Cybersecurity Source Documents

A host-based intrusion detection system (HIDS) monitors a computer system for suspicious activity by analyzing events occurring within that host. It can detect malicious activities and security policy violations by examining system calls, application logs, file-system modifications (such as rootkit installations), and other host activities. HIDS is an essential component in safeguarding the IT infrastructure against unauthorized access and security breaches.
References := The Understanding Cisco Cybersecurity Operations Fundamentals (CBROPS) course material covers the monitoring of alerts and breaches, and the understanding and following of established procedures for response to alerts converted to incidents, which includes the use of host-based intrusion detection systems

Running all processes as root or administrator violates the principle of least privilege, which states that users and processes should be granted only the minimum permissions necessary to perform their specific role or function within an organization. Running all processes as root or administrator gives them full access and control over the system, which increases the risk of unauthorized actions, malicious attacks, and accidental errors. It also makes it easier for attackers to escalate their privileges and compromise the system. References:
* Understanding Cisco Cybersecurity Operations Fundamentals (CBROPS) v1.0, Module 1: Security Concepts, Lesson 1.2: Security Principles
* Cisco Certified CyberOps Associate Overview, Exam Topics, 1.1 Explain the CIA triad

The /var/log/auth.log file contains information about authentication and authorization events on a Linux system, such as successful and failed logins, sudo commands, and SSH sessions. The output in the exhibit shows a failed login attempt from a user named "root" using SSH. References: https://www.cisco.com/c/en/us
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