There is no application set to open the URL ksec://openFromLoginItem.

1 - Suggest restarting in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal.

2 - Does the issue present in this mode ?

Visit System Preferences > User & Groups > Login Items. Select anything that is there and remove [-] it. Then reboot and see if this message has gone away.

 Suggest downloading the Application Etrecheck directly from a well Respected ASC Contributor. And Safe to use.

The application is free or paid from added features. 

Run the application with Full Disc Access ( Security & Privacy - Full Disc Access ).

It will take a Snap Shot -  both the hardware and software.

 The Report will Not Reveal Any Personal Information. 

Post back the Full Report - copy and paste - using the Additional Text Icon ( 3rd Icon to last )

We can have a look at the report for possible issues and may have possible suggestions to resolve the issues.

Any Third Party Applications that will interfere with the normal operation of the OS, alter, modify, remove or delete or attempt to do so is an invitation for disaster and may require a Reinstallation of the OS in-order to replace any modified, altered, removed or corrupted elements of the OS this software has inflected on this computer 

Any of the below should be removed as per Developers Instructions 

This includes AntiVirus, Disk Cleaners, Disk Optimizes, UnInstaller etc.

This will include CleanMyMac , This will include BitDefender , 

This will included Norton Antivirus , Sophos Av Software

Intego AntiVirus, McAfee, MacKeeper, Avast AntiVirus

Ad Guard, Webroot

The The Built in Security  is all that is required.

OK I’m getting this message to I’m curious does this mean my security was compromised because I feel as if somebody’s been remotely accessing my computer and I’m getting that message because I started to delete things that I thought might be the reason for the security being compromise but I am not 100% sure as to exactly what I’m doing all I know is that I came home and all my desktop had been ran through so I’m not exactly sure what is going on it’s just it all my files were open and on display when they weren’t previously on display it was extremely strange somebody had definitely altered my computer and I’m trying to figure out what exactly is the best way to go about handling this to ensure the integrity of my security of my Apple it’s a 27 inch iMac late 2015 retina 5k 3.2 ghz quad core intel core i5

Download and install the free Malwarebytes for Mac, and run it. See if it detects any adware/malware. At your option, you can remove Malwarebytes afterward from its Help menu. It is a 14-day trial of full features, and afterward, it disables the full features, and remains an (unpaid) useful tool.

When these Finder ksec URI began appearing, had you recently installed any browser extensions or software downloaded from sites other than from the original developer?