According to the CISM Review Manual (Digital Version), page 212, the incident response process consists of six phases: preparation, identification, containment, eradication, recovery, and lessons learned. Containment is the phase where the incident response team isolates the affected systems or networks to prevent further damage or spread of the malware. Eradication is the phase where the incident response team removes the malware and any traces of its activity from the affected systems or networks. Recovery is the phase where the incident response team restores the normal operations of the systems or networks. Identification is the phase where the incident response team detects and analyzes the signs of the incident. Therefore, the information security manager should be confident that the malware has not continued to spread at the completion of the containment phase, which is the earliest phase where the incident response team can stop the propagation of the malware. References = 1: CISM Review Manual (Digital Version), page 212

A SIEM system is the best tool for providing an incident response team with the greatest insight into insider threat activity across multiple systems because it can collect, correlate, analyze, and report on security events and logs from various sources, such as network devices, servers, applications, and user activities. A SIEM system can also detect and alert on anomalous or suspicious behaviors, such as unauthorized access, data exfiltration, privilege escalation, or policy violations, that may indicate an insider threat. A SIEM system can also support forensic investigations and incident response actions by providing a centralized and comprehensive view of the security posture and incidents.
References: The CISM Review Manual 2023 defines SIEM as "a technology that provides real-time analysis of security alerts generated by network hardware and applications" and states that "SIEM systems can help identify insider threats by correlating user activity logs with other security events and detecting deviations from normal patterns" (p. 184). The CISM Review Questions, Answers & Explanations Manual 2023 also provides the following rationale for this answer: "A security information and event management (SIEM) system is the correct answer because it can provide the most insight into insider threat activity across multiple systems by collecting, correlating, analyzing, and reporting on security events and logs from various sources" (p. 95). Additionally, the Detecting and Identifying Insider Threats article from the CISA website states that
"threat detection and identification is the process by which persons who might present an insider threat risk due to their observable, concerning behaviors come to the attention of an organization or insider threat team.
Detecting and identifying potential insider threats requires both human and technological elements" and that
"technological elements include tools such as security information and event management (SIEM) systems, user and entity behavior analytics (UEBA) systems, and data loss prevention (DLP) systems, which can monitor, analyze, and alert on user activities and network events" (p. 1)1.

An information security policy is the MOST helpful for aligning security operations with the IT governance framework because it defines the security objectives, principles, standards, and guidelines that guide the security operations activities and processes. An information security policy also establishes the roles and responsibilities, authorities and accountabilities, and reporting and communication mechanisms for security operations. An information security policy should be aligned with the IT governance framework, which provides the direction, structure, and oversight for the effective management and delivery of IT services and resources. An information security policy should also be consistent with the enterprise governance framework, which sets the vision, mission, values, and goals of the organization12. A security risk assessment (A) is helpful for identifying and evaluating the security risks that may affect the security operations and the IT governance framework, but it is not the MOST helpful for aligning them. A security risk assessment should be based on the information security policy, which defines the risk appetite, tolerance, and criteria for the organization12. A security operations program (B) is helpful for implementing and executing the security operations activities and processes that support the IT governance framework, but it is not the MOST helpful for aligning them. A security operations program should be derived from the information security policy, which provides the strategic direction and guidance for the security operations12. A business impact analysis (BIA) (D) is helpful for determining the criticality and priority of the business processes and functions that depend on the security operations and the IT governance framework, but it is not the MOST helpful for aligning them. A BIA should be conducted in accordance with the information security policy, which specifies the business continuity and disaster recovery requirements and objectives for the organization12. References = 1: CISM Review Manual 15th Edition, page 75-76, 81-82, 88-89, 93-941; 2:
CISM Domain 1: Information Security Governance (ISG) [2022 update]2

Reviewing the results of the vendor's independent control reports is the best way to assess the risk associated with using a SaaS vendor because it provides an objective and reliable evaluation of the vendor's security controls and practices. Independent control reports, such as SOC 2 or ISO 27001, are conducted by third-party auditors who verify the vendor's compliance with industry standards and best practices. These reports can help the customer identify any gaps or weaknesses in the vendor's security posture and determine the level of assurance and trust they can place on the vendor.
Verifying that information security requirements are included in the contract is a good practice, but it does not provide sufficient assurance that the vendor is actually meeting those requirements. The contract may also have limitations or exclusions that reduce the customer's rights or remedies in case of a breach or incident.
Requesting customer references from the vendor is not a reliable way to assess the risk associated with using a SaaS vendor because the vendor may only provide positive or biased references that do not reflect the true experience or satisfaction of the customers. Customer references may also not have the same security needs or expectations as the customer who is conducting the assessment.
Requiring vendors to complete information security questionnaires is a useful way to gather information about the vendor's security policies and procedures, but it does not provide enough evidence or verification that the vendor is actually implementing and maintaining those policies and procedures. Information security questionnaires are also subject to the vendor's self-reporting and interpretation, which may not be accurate or consistent. References = CISM Review Manual 15th Edition, page 144 SaaS Security Risk and Challenges - ISACA1 SaaS Security Checklist & Assessment Questionnaire | LeanIX2 Risk Assessment Guide for Microsoft Cloud3