A particular string of character sent by text message can cause an iPhone’s messaging app to crash, or shut down the phone.
The message, revealed on Reddit late Tuesday, seems to exploit an inability of the app’s preview feature to correctly render the characters, which are not the standard alphanumerics or emoticons one typically texts. After repeated attempts, the app crashes, leaving the user unable to send or receive texts as usual.
If the message is received while the phone is on the lock screen, it causes the phone to reboot.
Many iPhone owners took to Twitter Wednesday complaining they were hit.
Whoever discovered that weird iPhone thing that turns someone else's phone off… I hate you. I hate you so much. Why have you done this.
— Andrea Russett (@AndreaRussett) May 27, 2015
Users on Reddit reported that the text also works via the messaging app WhatsApp and that it affects Apple Watches as well as iPhones.
CNET senior editor Jeff Bakalar described the exploit as a popular prank that can only be perpetrated by someone who has your phone number. “It’s probably not going to happen to you unless someone you know, who has your number, targets you,” he told CBS News.