Which action should be prioritized by an IS auditor when they discover sensitive data being stored insecurely?

Prioritizing the introduction of immediate encryption measures is a proactive approach to safeguarding sensitive data found to be stored insecurely. Encryption serves as a critical mechanism for protecting data confidentiality, ensuring that even if unauthorized access occurs, the data remains unreadable and secure against potential exploitation.

In a situation where sensitive data is at risk, taking swift action to encrypt that data not only mitigates the immediate threat but also aligns with best practices in data protection. This immediate response is crucial, particularly in environments governed by regulations that mandate stringent data protection measures.

While documenting findings, notifying management, and conducting a full audit are essential steps in the overall audit process, they do not directly address the urgent need to secure the sensitive data. Encryption provides a tangible and effective preventative measure that helps reduce vulnerability and enhances the overall data security posture of the organization. Thus, prioritizing encryption effectively addresses the critical issue at hand, ensuring the sensitive information is protected as soon as possible.