The hashes of important files like system executables should match the information given by the RPM database. Executables with erroneous hashes could be a sign of nefarious activity on the system.
Check
The following command will list which files on the system have file hashes different from what is expected by the RPM database:
Given output from the check command, identify the package that provides the output and reinstall it. The following trimmed example output shows a package that has failed verification, been identified, and been reinstalled: