Errors like that caused me to nevermore use mirrorcache.opensuse.org in repo URLs. Switch to download.opensuse.org and reliability should be better. You may need only to wait a few hours and try again.
Lazy Kent is a member here, thus you can search him in the member lists (and PM him if you feel the urge).
You must have automated some update action. Updates do not start “out of the blue”. Maybe the desktop applet?
It is strange that you have a repository configured that you do not know of. Maybe some one-click installation where you did not take care on what happened? Make a list
The reason I reacted as I did is that I have been subject to a lot of ‘interesting things’ lately (my credit card used in the USA while I used it
for taxi in Ukraine while I physically was in Norway, several attempts to break into my PC running Windows 10 etc.). Moreover, I have
never fooled around with micro-cache, but only installed updates as they have become available.