The first step that an IS auditor should take when finding that a business impact analysis (BIA) has not been performed is to evaluate the impact on current disaster recovery capability. A BIA is a process that identifies and analyzes the potential effects of disruptions to critical business functions and processes. A BIA helps determine the recovery priorities, objectives, and strategies for the organization. Without a BIA, the disaster recovery plan may not be aligned with the business needs and expectations, and may not provide adequate protection and recovery for the most critical assets and activities. Therefore, an IS auditor should assess how the lack of a BIA affects the current disaster recovery capability and identify any gaps or risks that need to be addressed.
Performing a BIA, issuing an intermediate report to management, and conducting additional compliance testing are not the first steps that an IS auditor should take when finding that a BIA has not been performed.
These steps may be done later in the audit process, after evaluating the impact on current disaster recovery capability. Performing a BIA is not the responsibility of the IS auditor, but of the business owners and managers. Issuing an intermediate report to management may be premature without sufficient evidence and analysis. Conducting additional compliance testing may not be relevant or necessary without a clear understanding of the disaster recovery requirements and objectives.

The auditor should be most concerned about the security policy documents being available on a public domain website. This is because this exposes the organization's security posture and strategy to potential attackers, who can exploit the information to launch targeted attacks or bypass the security controls. The security policy documents should be classified as confidential and protected from unauthorized access or disclosure. The other options are less severe than exposing the security policy documents to the public, although they may also indicate some gaps or weaknesses in the security policy development, implementation, or maintenance process. References:
* CISA Review Manual (Digital Version), Chapter 5, Section 5.31
* CISA Online Review Course, Domain 3, Module 1, Lesson 12

Comprehensive and Detailed in-Depth Explanation:
A passive attack involves monitoring or listening without altering data or system operations. Eavesdropping is a classic example, where attackers intercept data without affecting the transmission.
Keystroke logging (Option A) and phishing (Option D) are active attacks. Piggybacking (Option B) involves unauthorized access and is also active.
ISACA CISA Reference: Domain 5 - Protection of Information Assets

Discovery sampling is an appropriate sampling method for an IS auditor who intends to launch an intensive investigation if one exception is found. Discovery sampling is a type of attribute sampling that determines the sample size based on an acceptable risk of not finding at least one occurrence of an attribute when a given rate of occurrence exists in a population. Discovery sampling can be used by an IS auditor who wants to detect fraud or errors that have a low probability but high impacton an audit objective. The other options are not appropriate sampling methods for this purpose, as they may involve judgmental sampling, variable sampling, or stratified sampling. References:
CISA Review Manual (Digital Version), Chapter 2, Section 2.31
CISA ReviewQuestions, Answers and Explanations Database, Question ID 230

The most important thing for an IS auditor to determine during the detailed design phase of a system development project is that acceptance test criteria have been developed. Acceptance test criteria define the expected functionality, performance and quality of the system, and are used to verify that the system meets the user requirements and specifications. The IS auditor should ensure that the acceptance test criteria are clear, measurable and agreed upon by all stakeholders. Program coding standards have been followed is something that the IS auditor should check during the coding or testing phase, not the detailed design phase.
Data conversion procedures have been established or the design has been approved by senior management are things that the IS auditor should verify during the implementation phase, not the detailed design phase. References: ISACA, CISA Review Manual, 27th Edition, 2018, page 323