"System software from the following developers was updated...", but no descriptions

Download and run Etrecheck.  Copy and paste the results into your reply. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support  to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.

Copy the report

and use the Additional Text button to paste the report in your reply.

Then we can evaluate the report to see if we can determine what software is giving you the message.

If your Mac is a production Mac required for your work you might not want to have automatic updates turned on. That's because if there is an issue in compatibility with an update and your production software you could be tied up for a while reinstalling the old system.

If yo have a second drive, an external SSD that you've cloned your boot drive to with Carbon Copy Cloner you can update it when updates come along and to check and make sure all apps work as needed.

Just some food for thought.

Uninspired Alias wrote:

I've spent all day fighting whatever this thing is, and I appear to have finally won. It tried to keep me from turning on security features, from installing security updates, from restarting to complete the installs, etc, but I was able to find workarounds each time. I then combed through every file in the system and user libraries, and of course, applications, and deleted about a hundred questionable things. I'm now in the process of changing a couple hundred passwords. Fun fun fun! But thanks again for your tip.

Wait! Stop! That requisition to post an EtreCheck report was specifically to locate those mysterious Login Items which your EtreCheck report would have clearly showed, had you posted it.

Instead, you posted a screenshot from EtreCheck, which is a really, really bad idea because screenshots do not have personal information removed.

Now you are deleting hundreds of things and changing passwords all day? STOP!!!!

If you have questions, ask. That's all you need to do. 2 minutes, you have your answer.

I have no idea what you have done. I have no idea if you have actually re-enabled Apple security updates, which takes less than 2 minutes by the way. And you are still no closer to getting the answer you are looking for.

If someone asks you to post an EtreCheck report, please do that. You don't have to if you don't want to. That's fine. But please do not go on some mysterious question from something you think you might have seen in the report. There are people all around, Old Toad, Etresoft support, who will answer any question you have in minutes.

Control (right) - click on the app and select "Open" from the contextual menu. Then select Open again when asked. That should let you open the app.