I am in the process of transferring data from my old MacBook Pro to a new MacBook Pro. In order to transfer some files, I decided to plug in a USB hard drive that contained a bootable partition of my old MacBook Pro, as well as a partition that contained the files that I wished to transfer. (The drive contained a few partitions, all of which mounted on the new MacBook Pro).
I had my old MacBook Pro for about four years, and I never performed a fresh install. So since the bootable partition on the usb drive is an exact copy of my old MacBook Pro hard drive, if there were any malicious files, they would be sitting on the hard drive.
When I plugged in the hard drive to my new Mac, I did not open or run any files, I simply copied over a few specific files including some pictures that I took. I did not boot from the partition on the drive.
My understanding is that since macOS does not have autorun, I would have to actually copy infected files, or open or run an infected file (by clicking on it) in order to transfer or 'activate' malware or a virus, is this true?
So assuming that I did not copy or run any infected files from the hard drive, do I have anything to worry about? Is my new Mac at risk? Would it be safe to continue this practice of transferring files in the future?
Also, my new Mac is running macOS Sierra.
Note: I do not have an specific reason to believe that the old Mac is infected - it hasn't necessarily been behaving strangely, I am just cautious since it is an older machine that has four years worth of software installed.