MTTR (Mean Time to Repair) measures the average time required to repair a failed component or system and restore it to full functionality, making it the correct metric for estimating downtime due to a failed drive.

The shell would allow the attacker to gain unauthorized access and control over the server.

PDFs can be used to deliver malware such as embedded scripts or exploits. Enabling malware detection through a UTM helps to scan and block malicious content within uploaded files before they reach the server.

To demonstrate that the system can be restored to a working state in the event of a performance issue after deploying a change, the systems administrator must submit a backout plan. A backout plan outlines the steps to revert the system to its previous state if the new deployment causes problems.
Backout plan: Provides detailed steps to revert changes and restore the system to its previous state in case of issues, ensuring minimal disruption and quick recovery.
Impact analysis: Evaluates the potential effects of a change but does not provide steps to revert changes.
Test procedure: Details the steps for testing the change but does not address restoring the system to a previous state.
Approval procedure: Involves obtaining permissions for the change but does not ensure system recovery in case of issues.

Recurring training is a type of security awareness training that is conducted periodically to refresh and update the knowledge and skills of the users. Recurring training can help improve the situational and environmental awareness of existing users as they transition from remote to in- office work, as it can cover the latest threats, best practices, and policies that are relevant to their work environment. Modifying the content of recurring training can ensure that the users are aware of the current security landscape and the expectations of their roles.