Apple Inc has added a security feature across its operating systems to battle hacks into its devices that rely on incoming iMessages, it said on Thursday. Using a sophisticated spying tool called Karma, which relied on a flaw in Apple’s iMessage system, they accessed iPhones without requiring the targets to click on anything to establish a connection. While largely invisible to users, BlastDoor is present on iOS 14, the most recent version of Apple’s iPhone operating system, and systems for all its other devices, company officials said.