[PCI DSS 3.0] 10.5.5 Use file-integrity monitoring or change-detection software on logs to ensure that existing lo

10.5.5 Use file-integrity monitoring or change-detection software on logs to ensure that existing log data cannot be changed without generating alerts (although new data being added
should not cause an alert).

10.5.5 Examine system settings, monitored files, and results from monitoring activities to verify the use of file-integrity monitoring or change-detection software on logs.

File-integrity monitoring or change-detection systems check for changes to critical files, and notify when such changes are noted. For file- integrity monitoring purposes, an entity usually monitors files that don’t regularly change, but when changed indicate a possible compromise.