The following message will freeze an iPhone when received as an iMessage and displayed as a banner notification. Use responsibly.
This bug appears to only affect through iOS v10.1.1. 10.2+ does not seem vulnerable.
You will not be able to copy/paste this text on your iPhone. You must create a new note from icloud.com, open that note on your phone, and share via messages, or send via iMessage from a Mac.
Filip (EverythingApplePro) found a way to make this bug affect iOS 10.2+ upon receipt. Download this contact file and send it via iMessage. You must save into iCloud drive before sending if on iOS.Technical explanation
Click this fix by @vincedes3 to fix broken messages application
Questions? My DMs are open on my Twitter