It was mid-morning on a Tuesday this month when a Ferrari NV executive started receiving a bunch of unexpected messages, seemingly from the CEO. “Hey, did you hear about the big acquisition we’re planning? I could need your help,” one of the messages purporting to be from Chief Executive Officer Benedetto Vigna read. The WhatsApp messages seen by Bloomberg didn’t come from Vigna’s usual business mobile number. The profile picture also was different, though it was an image of the bespectacled CEO...