This is best explained by credentialed scanning because the scanner is given administrator-level credentials, and the SIEM confirms successful logins occurred during the scan. Credentialed scans authenticate to the target systems (via SMB/WMI/WinRM for Windows, SSH for Linux/Unix, APIs for certain platforms) and then perform deeper inspection from an “inside” perspective. That allows the scanner to enumerate details that are not reliably visible from unauthenticated network probing—such as installed patch levels, local security policy settings, registry permissions, configuration files, running services with their exact versions, and misconfigurations that require local access to verify.
The scenario’s outcomes strongly match this: the scan takes significantly longer, which is common because authenticated checks involve logging in and performing many local queries; the results include weak registry permissions, outdated patches, and insecure configuration files, all of which typically require authenticated access to assess comprehensively. In addition, credentialed scanning reduces false positives and improves accuracy, because it can confirm vulnerability conditions directly rather than inferring from banners or open ports.
Why the other options are less accurate:
Non-credentialed scanning (D) is performed from an external perspective without logins; it would not normally retrieve detailed registry/config file permission findings, and SIEM logs would not show successful authentication events caused by the scanner.
External scanning (A) describes the scan’s network location (outside the organization) rather than the authentication mode. You can do external credentialed scans, but the defining feature here is authenticated logins and deep host checks.
Internal scanning (C) also refers to where the scan originates. While the scan might be internal, the question’s key differentiator is that admin credentials were used to log in and gather detailed local information.
Therefore, the scan type is B. Credentialed Scanning.
