What is the purpose of the process RelayUploader in macOS?
This isn't a proper answer, just some things you may want to try: 


RelayUploader (aka Relay.Uploader) seems to be associated with a company called TechSmith... do you have any of their apps? 
If you have a malware of virus scanner, you should run a scan on it.
Have you looked at the info available in Activity Monitor? (If not, open Activity Monitor, select the process from the list, then click the i icon in the Activity Monitor dialog). What does it say in the Open Files and Ports tab? Do you recognize any of these files?