It’s never wise to underestimate an enemy. I just know for fact, that the Minuteman II ICBMS used an operating system that was so obsolete it was loaded on 5.25 inch floppy disks. No modern computer can talk to them even IF they were network capable, which they are not. All connections are hardened, shielded, and totally isolated.
If your ever near Minot North Dakota, you can take a tour of an abandoned Minuteman II launch control facility. It’s cool as hell if that sort of thing interest you. I thoroughly enjoyed it. As far as the Minuteman III missiles, which is the current version I have no idea, as that’s classified out the wazzou.