The most effective way to identify exfiltration of sensitive data by a malicious insider is to establish behavioral analytics monitoring. Behavioral analytics is the process of analyzing the patterns and anomalies in user behavior to detect and prevent insider threats. Behavioral analytics can help identify unusual or suspicious activities, such as accessing sensitive data at odd hours, transferring large amounts of data to external devices or locations, or using unauthorized applications or protocols. Behavioral analytics can also help correlate data from multiple sources, such as network logs, user profiles, and access rights, to provide a holistic view of user activity and risk.
Data loss prevention (DLP) software is a tool that can help prevent exfiltration of sensitive data by a malicious insider, but it is not the most effective way to identify it. DLP software can block or alert on unauthorized data transfers based on predefined rules and policies, but it may not be able to detect sophisticated or stealthy exfiltration techniques, such as encryption, steganography, or data obfuscation.
Reviewing perimeter firewall logs is a way to identify exfiltration of sensitive data by a malicious insider, but it is not the most effective way. Perimeter firewall logs can show the traffic volume and destination of data transfers, but they may not be able to show the content or context of the data. Perimeter firewall logs may also be overwhelmed by the amount of normal traffic and miss the signals of malicious exfiltration.
Providing ongoing information security awareness training is a way to reduce the risk of exfiltration of sensitive data by a malicious insider, but it is not a way to identify it. Information security awareness training can help educate users on the importance of protecting sensitive data and the consequences of violating policies and regulations, but it may not deter or detect those who are intentionally or maliciously exfiltrating data.
References:
* ISACA, CISA Review Manual, 27th Edition, 2019, p. 300
* ISACA, CISA Review Questions, Answers & Explanations Database - 12 Month Subscription 1
* Cybersecurity Engineering for Legacy Systems: 6 Recommendations - SEI Blog 2
* How to Secure Your Company's Legacy Applications - iCorps

The most significant benefit of implementing a control self-assessment (CSA) program and leveraging the internal audit function to test its internal controls annually is that risks are detected earlier. A CSA program is a process that enables business owners and managers to assess and improve their own internal controls on a regular basis, without relying on external auditors or consultants. A CSA program can help identify and mitigate risks, enhance performance, increase accountability, and foster a culture of control within the organization. By leveraging the internal audit function to test its internal controls annually, a small business unit can also obtain independent assurance and validation of its CSA results, as well as recommendations for improvement. This approach can help reduce compliance costs, as external audits may be less frequent or extensive. However, this is not the most significant benefit, as compliance costs are only one aspect of the total cost of risk. Business owners can also focus more on their core roles, as they can delegate some of their control responsibilities to their staff or teams through CSA. However, this is not the most significant benefit, as business owners still need to oversee and monitor their CSA activities and results, and ensure that they align with their strategic objectives and priorities. Line management may also be more motivated to avoid control exceptions, as they are directly involved in assessing and improving their own controls through CSA.
However, this is not the most significant benefit, as motivation alone may not be sufficient to ensure effective control design and operation. References: Info Technology & Systems Resources | COBIT, Risk, Governance
... - ISACA, IT Governance and Process Maturity

The greatest concern with the lack of structure for technology risk governance is C. Key decision-making entities for technology risk have not been identified. Technology risk governance is the process of establishing and maintaining the policies, roles, responsibilities, and accountabilities for managing technology risks within an organization1. Technology risk governance requires a clear organizational structure that defines who has the authority and responsibility to make decisions, set objectives, allocate resources, monitor performance, and ensure compliance for technology risk management2. Without such a structure, an organization may face the following challenges:
Lack of alignment and integration between technology and business strategies, leading to suboptimal outcomes and missed opportunities.
Lack of clarity and consistency in technology risk identification, assessment, mitigation, and reporting, leading to gaps and overlaps in risk coverage and exposure.
Lack of communication and collaboration among different stakeholders involved in technology risk management, leading to conflicts and inefficiencies.
Lack of oversight and accountability for technology risk management activities and results, leading to poor quality and reliability.