The auditor's best course of action after a security breach in which a hacker exploited a well-known vulnerability in the domain controller is to determine if the logs were monitored. Log monitoring is an essential control for detecting and responding to security incidents, especially when known vulnerabilities exist in the system. The auditor should assess if the logs were properly configured, collected, reviewed, analyzed, and acted upon by the responsible parties. Updating patches, monitoring network traffic, and classifying domain controllers for high availability are also important controls, but they are not directly related to the detection and response of the security breach. References:
* CISA Review Manual (Digital Version), page 301
* CISA Questions, Answers & Explanations Database, question ID 3340

A post-implementation review (PIR) is an assessment conducted at the end of a project cycle to determine if the project was indeed successful and to identify any existing flaws in the project1. One of the main objectives of a PIR is to evaluate the outcome and functional value of a project1. Therefore, an IS auditor should be most concerned with whether the system meets the intended requirements and delivers the expected benefits to the stakeholders. A system that does not have a maintenance plan is a major risk, as it may not be able to cope with changing needs, fix errors, or prevent security breaches. A maintenance plan is essential for ensuring the system's reliability, availability, and performance in the long term2.
The other options are less critical for a PIR, as they are more related to the project management aspects than the system quality aspects. The system may contain several minor defects that do not affect its functionality or usability, and these can be resolved in future updates. The system deployment may be delayed by three weeks due to unforeseen circumstances or dependencies, but this does not necessarily mean that the system is faulty or ineffective. The system may be over budget by 15% due to various factors such as scope creep, resource constraints, or market fluctuations, but this does not imply that the system is not valuable or beneficial.
References: 1: Post-Implementation Review Best Practices - MetaPM 2: What is Post-Implementation Review in Project Management?

Social engineering exploits human vulnerabilities, and the most effective mitigation is training employees to recognize and respond to these threats. Security awareness programs help build a culture of vigilance, equipping employees with the knowledge to identify phishing attempts, suspicious behavior, and other social engineering tactics.
* Multi-factor Authentication (MFA) (Option A): Enhances access control but does not address the human vulnerability to social engineering.
* Access History Log Review (Option C): Useful for post-incident analysis but does not prevent incidents.
* File Encryption with Password Protection (Option D): Adds security layers but is ineffective if the password is compromised.
Reference: ISACA CISA Review Manual, Job Practice Area 4: Protection of Information Assets.

The primary purpose of documenting audit objectives when preparing for an engagement is to identify areas with relatively high probability of material problems. Audit objectives are statements that describe what the audit intends to accomplish or verify during the engagement. Audit objectives help the IS auditor to focus on the key areas of risk or concern, to design appropriate audit procedures and tests, and to evaluate audit evidence and results. By documenting audit objectives, the IS auditor can identify areas with relatively high probability of material problems that may affect the achievement of audit goals or business objectives.
Addressing the overall risk associated with the activity under review, ensuring maximum use of audit resources during the engagement and prioritizing and scheduling auditee meetings are also purposes of documenting audit objectives, but they are not as primary as identifying areas with high probability of material problems. References:
* CISA Review Manual, 27th Edition, page 1111
* CISA Review Questions, Answers & Explanations Database - 12 Month Subscription