The discovery of unapproved accounts accessing shared data, along with data discrepancies, strongly indicates unauthorized changes.

Indicators of Unauthorized Changes:

Unexpected user permissions found during audits​.

Modified or deleted data without proper documentation.

Altered system or security configurations, allowing unintended access.

Why Not Other Options?

A. Filesystem Anomaly: This refers to unexpected behavior in the file structure, such as corrupt metadata or missing files, rather than unauthorized user access.

B. Illegal Software: Would involve unlicensed or unauthorized applications, not unauthorized file modifications.

D. Data Exfiltration: If data was removed, it might be exfiltration, but in this case, data modifications were detected instead.

To prevent unauthorized changes, security teams should use:

File Integrity Monitoring (FIM) to detect unauthorized modifications.

Access control audits to verify correct user permissions.

SIEM tools to analyze logs for anomalies.