Isaca Updated CISA Exam Questions and Answers by florrie

Signature-based intrusion detection systems (IDS) are systems that compare network traffic with predefined patterns of known attacks, called signatures. The effectiveness of signature-based IDS depends on how well they can detect new or unknown attacks that are not in their signature database. Therefore, an increase in the number of detected incidents not previously identified is the best indicator of the effectiveness of signature-based IDS, as it shows that they can recognize novel or modified attacks. 

Mapping IT processes to roles is an activity that provides an IS auditor with the most insight regarding potential single person dependencies that might exist within the organization. Single person dependencies occur when only one person has the knowledge, skills, or access rights to perform a critical IT function. Mapping IT processes to roles can help to identify such dependencies and assess their impact on the continuity and security of IT operations. The other activities do not provide as much insight into single person dependencies, as they do not show the relationship between IT processes and roles. References: CISA Review Manual, 27th Edition, page 94

Understanding the specific agile methodology that will be followed is the first step that an IS auditor should do to ensure the effectiveness of the project audit. An IS auditor should familiarize themselves with the agile approach, principles, practices, and tools that will be used by the project team, as well as the roles and responsibilities of the project stakeholders. This will help the IS auditor to identify and assess the relevant risks and controls for the project audit. The other options are not the first steps that an IS auditor should do, but rather possible subsequent actions that may depend on the specific agile methodology. References:

CISA Review Manual (Digital Version), Chapter 4, Section 4.3.21

CISA Review Questions, Answers & Explanations Database, Question ID 211