You haven't specified anything in inputs.conf for Splunk to look for. Splunk uses API calls tp monitor these logs, which are in binary format. Adding this stanza in inputs.conf on the UF will help. Please make sure that the Index is already created on your Indexer/s. Also, after pasting this on your inputs.conf, please make sure to restart splunkd on the DC.
[WinEventLog://Security]
disabled = 0
index = your_index_name
I'll also suggest you to use a server as a deployment server for the UFs. That way, you can compartmentalize your UFs according to the types of servers on which they are deployed, example: Domain controllers, any app's database, DHCP servers etc. Also, you can change their inputs.conf anytime from the deployment server, rather than going to the servers to make the changes all the time. Will become increasingly difficult, as your environment grows.
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