So I recently upgraded an old MB Pro to Mojave because I was concerned I could've infected it.
Now I'm probably overreacting to all of this but since I was using all of my USB sticks in the previous version, lets say the malware had created backdoors to each and every USB stick I've ever plugged in there.
Is there any way I can retrieve the files from my USB sticks safely/make the sticks safely usable again? I suppose that if my files were infected too, they'd have to exploit some vuln in the viewer I'm using (Preview) but as far as I'm aware, there aren't any exploits for it. (Edit : Apparently there is one in CVEdetails CVE-2007-0729 but it's for a very old version of Preview)
And stretching it even further, could the infected files attack the USB firmware? Or would physical access to the stick be needed to do so?
Thanks and sorry if this is not in the correct section.