The EC-Council Incident Handler (ECIH) curriculum emphasizes Identity and Access Management (IAM) as a foundational control in cloud security. In cloud environments, shared credentials and lack of role-based restrictions significantly increase the risk of misuse, unauthorized access, and privilege abuse.

The scenario clearly identifies two major violations: credential reuse across departments and absence of role-specific restrictions. ECIH highlights that cloud best practices require enforcing strict user access control using the Principle of Least Privilege (PoLP) and role-based access control (RBAC). Each user—including third-party contractors—must have unique credentials with clearly defined permissions aligned strictly with their job responsibilities.

Credential isolation ensures accountability and traceability, enabling effective logging, auditing, and forensic investigation. Without unique user tracking, organizations cannot accurately attribute actions, which weakens incident response and compliance efforts.

Option B (data anonymization) relates to data privacy but does not address access misuse. Option C (vulnerability scanning of mobile apps) addresses application security, not identity misuse. Option D (SSL encryption) protects data in transit but does not prevent unauthorized credential reuse or excessive access rights.

ECIH strongly recommends implementing multi-factor authentication (MFA), enforcing strong IAM policies, restricting third-party access, and continuously monitoring privileged accounts in cloud environments. Therefore, enforcement of strict user access control and credential isolation is the most appropriate preventive measure.