I wonder how many USB storage devices have had their firmware infected without anybody ever even knowing about it like SD cards and other sorts of storage devi

I wonder how many USB storage devices have had their firmware infected without anybody ever even knowing about it like SD cards and other sorts of storage devices with embedded microcomputers; why storage? for a huge binary payload for the host system! all it takes is one super secret 64-bit instruction that makes the cpu drop its pants and bend over, or one super secret exploit