Explanation
Containment is the action that MUST happen immediately following the identification of a malware incident because it aims to isolate the affected systems or networks from the rest of the environment and prevent the spread or escalation of the malware. Containment can involve disconnecting the systems or networks from the internet, blocking or filtering certain ports or protocols, or creating separate VLANs or subnets for the isolated systems or networks. Containment is part of the incident response process and should be performed as soon as possible after detecting a malware incident12. Preparation (A) is the phase that happens before the identification of a malware incident, where the organization establishes the incident response plan, team, roles, resources, and tools. Preparation is essential for ensuring the readiness and capability of the organization to respond to malware incidents effectively and efficiently12. Recovery (B) is the phase that happens after the containment and eradication of a malware incident, where the organization restores the normal operations of the systems or networks, verifies the functionality and security of the systems or networks, and implements the preventive and corrective measures to avoid or mitigate future malware incidents. Recovery is the final phase of the incident response process and should be performed after ensuring that the malware incident is fully resolved and the systems or networks are clean and secure12. Eradication (D) is the phase that happens after the containment of a malware incident, where the organization removes the malware and its traces from the systems or networks, identifies the root cause and impact of the malware incident, and collects and preserves the evidence for analysis and investigation. Eradication is an important phase of the incident response process, but it does not happen immediately after the identification of a malware incident12. References = 1: CISM Review Manual 15th Edition, page 308-3091; 2: Cybersecurity Incident Response Exercise Guidance - ISACA2

Self-assessments provide the best feedback on readiness and permit identification of items requiring remediation. Directing regulators to a specific person or department, or assessing previous reports, is not as effective. The legal department should review all formal inquiries but this does not help prepare for a regulatory review.

The data owner is responsible for applying the proper classification to the data. Senior management is ultimately responsible for the organization. The security officer is responsible for applying security protection relative to the level of classification specified by the owner. The technology group is delegated the custody of the data by the data owner, but the group does not classify the information.

Explanation
Senior management seeks to understand the business justification for investing in security. This can best be accomplished by tying security to key business objectives. Senior management will not be as interested in technical risks or examples of successful attacks if they are not tied to the impact on business environment and objectives. Industry best practices are important to senior management but, again, senior management will give them the right level of importance when they are presented in terms of key business objectives.

Encrypting by the sender's private key ensures authentication. By being able to decrypt with the sender's public key, the receiver would know that the message is sent by the sender only and the sender cannot deny/repudiate the message. By encrypting with the sender's public key secondly, only the sender will be able to decrypt the message and confidentiality is assured. The receiver's private key is private to the receiver and the sender cannot have it for encryption. Similarly, the receiver will not have the private key of the sender to decrypt the second-level encryption. In the case of encrypting first by the sender's private key and. second, decrypting by the sender's public key, confidentiality is not ensured since the message can be decrypted by anyone using the sender's public key. The receiver's private key would not be available to the sender for second-level encryption. Similarly, the sender's private key would not be available to the receiver for decrypting the message.