FIM stores the files checksums and other attributes in a local FIM database. Upon a scan, the Wazuh agent reports any changes the FIM module finds in the monitored paths to the Wazuh server. The FIM module looks for file modifications by comparing the checksums of a file to its stored checksums and attribute values.
I don't know if this is the tool you are looking for. Can you elaborate a bit more about Alienvault and what you need to do with it?