I have reason to suspect that somebody may have had unauthorized access to my computer. I've just reset my copy of OS X from the recovery partition. Afterwards, I was prompted twice to update my OS via the App Store. One of these I may have selected through a notification; the second I selected through the App Store. I'm now on 10.13.6.
Is there a way now to make sure both of these updates were legitimately provided by Apple?
Relatedly, if somebody wanted to install malware of some kind into the recovery partition of my MacBook, is there any way either to scan and remove that or to replace that portion of the hard drive with a legitimate version of the partition?