Details
In order to mitigate firmware attacks Apple has created an automated Firmware check to ensure that the EFI version running is a known good version from Apple. There is also an automated process to check it every seven days.
Rationale:
If the Firmware of a computer has been compromised the Operating System that the Firmware loads cannot be trusted either.
Solution
If EFI does not pass the integrity check you may send a report to Apple. Backing up files and clean installing a known good Operating System and Firmware is recommended.
Supportive Information
The following resource is also helpful.
This security hardening control applies to the following category of controls within NIST 800-53: System and Services Acquisition.This control applies to the following type of system Unix.