A newly discovered bug in Apple’s iOS mobile operating system is being exploited in a prank that lets anyone crash your iPhone or iPad by just sending an emoji-filled iMessage. YouTube star EverythingApplePro published a video highlighting a sequence of characters that temporarily freeze and restart an iPhone. As soon as this text is received, the iPhone’s software attempts to combine the emojis but fails, and the messaging app crashes and eventually reboots in a few minutes. The recipients do not even have to open or read the message.
Source: https://thehackernews.com/2017/01/crash-iphone-emoji.html