The first thing that should be done when an intrusion into an organization network is detected is to identify nodes that have been compromised. Identifying nodes that have been compromised is a critical step in responding to an intrusion, as it helps determine the scope, impact, and source of the attack, and enables the implementation of appropriate containment and recovery measures. The other options are not the first things that should be done when an intrusion into an organization network is detected, as they may be premature or ineffective without identifying nodes that have been compromised. Blocking all compromised network nodes is a containment measure that can help isolate and prevent the spread of the attack, but it may not be possible or feasible without identifying nodes that have been compromised. Contacting law enforcement is a reporting measure that can help seek external assistance and comply with legal obligations, but it may not be necessary or appropriate without identifying nodes that have been compromised. Notifying senior management is a communication measure that can help inform and escalate the incident, but it may not be urgent or accurate without identifying nodes that have been compromised. References: CISA Review Manual (Digital Version), Chapter 4, Section 4.2.2

This means that the organization should obtain the source code from the escrow agent and compare it with the current version of the application that they are using. The organization should then identify and apply any changes or updates that are missing or different in the escrow version, so that it matches the current version.
This way, the organization can ensure that they have a complete and accurate copy of the source code that reflects their current needs and requirements.
Bringing the escrow version up to date can help the organization to avoid or reduce the risks and costs associated with using an outdated or incompatible version of the source code. For example, an older version of the source code may have bugs, errors, or vulnerabilities that could affect the functionality, security, or performance of the application. An older version of the source code may also lack some features, enhancements, or integrations that could improve the usability, efficiency, or value of the application. An older version of the source code may also not comply with some standards, regulations, or contracts that could affect the quality, reliability, or legality of the application1.
The other options are not as good as bringing the escrow version up to date for the organization. Option A, analyzing a new application that meets the current requirements, is a possible option but it may be more time- consuming, expensive, and risky than updating the existing application. The organization may have to go through a complex and lengthy process of selecting, acquiring, implementing, testing, and migrating to a new application, which could disrupt their operations and performance. The organization may also have to deal with compatibility, interoperability, or data quality issues when switching to a new application2. Option B, performing an analysis to determine the business risk, is a necessary step but not a recommendation for the organization. The organization should already be aware of the business risk of using an application whose vendor has gone out of business and whose escrow has an older version of the source code. The organization should focus on finding and implementing a solution to mitigate or eliminate this risk3. Option D, developing a maintenance plan to support the application using the existing code, is not a feasible option because it assumes that the organization has access to the existing code. However, this is not the case because the vendor has gone out of business and the escrow has an older version of the source code. The organization cannot support or maintain an application without having a complete and accurate copy of its source code.
References:
* How Important Is Source Code Escrow - ISACA1
* The What and Why of Source Code Escrow2
* Unlocking Source Code In Escrow 2023: A Guide To Secure Software3

Information security policies and procedures are the foundation of an organization's information security program. They define the roles, responsibilities, rules, and standards for protecting information assets from unauthorized access, use, disclosure, modification, or destruction. The most important factor when developing information security policies and procedures is to align them with an information security framework that provides a comprehensive and consistent approach to managing information security risks. An information security framework can also help ensure compliance with relevant regulations, inclusion of mission and objectives, and consultation with security staff. However, these factors are secondary to alignment with an information security framework. References: CISA Certification | Certified Information Systems Auditor | ISACA, CISA Review Manual (Digital Version)

A maturity model for a technology organization is a tool that measures the progress and capability of the IT function in relation to its goals, processes, and practices. A maturity model can help identify gaps and areas for improvement, as well as benchmark the IT function against industry standards or best practices. One of the key aspects of a maturity model is the definition and clarity of roles and responsibilities for the IT function and its stakeholders. A roles and responsibility matrix, such as a RACI matrix, is a document that clarifies who is responsible, accountable, consulted, and informed for each task or deliverable in a project or process.
A roles and responsibility matrix can help avoid confusion, duplication, or omission of work, as well as ensure accountability and communication among the IT function and its customers, partners, and suppliers.
Therefore, an IS auditor should focus on reviewing the roles and responsibility matrix when evaluating the maturity model for a technology organization.
A standard operating procedure (SOP) is a document that describes the steps and instructions for performing a routine or repetitive task or process. SOPs are important for ensuring consistency, quality, and compliance in the IT function, but they are not directly related to the maturity model. A service level agreement (SLA) is a contract that defines the expectations and obligations between an IT service provider and its customers. SLAs are important for ensuring customer satisfaction, performance measurement, and dispute resolution in the IT function, but they are not directly related to the maturity model. A business resiliency plan is a document that outlines how an IT function will continue to operate or recover from a disruption or disaster. Business resiliency is important for ensuring availability, reliability, and security in the IT function, but it is not directly related to the maturity model. References: 1: Maturity Models for IT & Technology | Splunk 2: Responsibility assignment matrix - Wikipedia 3: Roles and Responsibilities Matrix - SDLCforms

If an IS auditor finds that management did not address a prior period audit finding, the next course of action should be to interview management to determine why the finding was not addressed, as this would help to understand the root cause, the impact, and the risk level of the issue. Noting the exception in a new report, recommending alternative solutions, or conducting a risk assessment are possible subsequent steps, but they should not precede interviewing management. References: CISA Review Manual (Digital Version), Chapter
1, Section 1.6