A short, 5-second MP4 video is circulating online which causes iPhones to freeze and lock up, with the only way around it being to perform a forced reboot of the device.

The video originates from the Weib video-sharing app Miaopai. The video doesn’t immediately cause your iPhone to crash, but around 10 second after watching it you’ll notice that your iPhone starts to slow down, before freezing completely.

The bug reportedly dates all the way back to iOS 5, and the older your handset, the faster the crash will occur. If you do get forwarded the link and find yourself the recipient of a crashed iPhone, perform a forced reboot by holding the power and home buttons of your iPhone until you see the Apple logo on-screen.

Apple itself has yet to respond to the bug, although this isn’t the first time a crash bug has been used to frustrate users. Earlier this year, a number of users started sharing links to the website CrashSafari dot com, which caused phones and PCs to crash by overloading their browsers with a self-generating address bar text string.

Hopefully Apple will sort out this particular bug with an iOS update in the near future. In the meantime, however, it’s best not to watch any suspicious video links you’re forwarded!