periodically I get a box which pops up on my mac saying that Apple wants to make changes and wants me to type in my password. the logon is correctly shown. Is this really apple and I put in my password everytime I start it.

As you have described it this seems to be very suspect. In my opinion the best approach would be to get in touch with Apple Support and ask them what this is all about, since it doesn't even seem to tell you what changes are to be made. Hopefully there will soon be others replying to this with perhaps different views, but personally I would never offer up my password in something like this, no matter how official it seems. Go the the source! Or perhaps what appears to be the source.

Gary

I a m having the same issue on my iMac 27 inch High Sierra10.13.6???? What is it what can be done and how do I stop it.. I have no malware installed should I if so which is best and works

Okay called them. Will see if it happens again and get a pic..THANKS!!

Same thing has been happening to me...