I think this is some misfired Ventura update. It downloads over 4GB at a snails pace. You can get rid of it only by deleting what you can from /var/folders/** and rebooting, but don't do that because after a while it will start the whole thing again, along with the big slow download.
if you do this in Terminal you should see its snapshot:
tmutil listlocalsnapshots /
e.g.
Snapshots for volume group containing disk /:
com.apple.os.update-BEED8AF7FA888DDD231CB3BD795A07D6D905B75AE0C88F2FF2651BED5E3DAC75
com.apple.os.update-MSUPrepareUpdate
the softwareupdate utility doesn't seem to know anything about it, there's nothing in /Library/Updates
I had one of these before, the common denominator seemed to be after an update to Safari Technology Preview, do you have that installed per chance
@Alvin777 ? Upgrades to Monterey seem to get shot of it, so probably best to wait for the next one IMHO.