The strange issue was discovered by Reddit users over the past few days. Opening a certain MP4 video on any iOS-powered device will cause the system to slow down, suffer from extreme lag and then lock up completely.
The bug was replicated in a video by EverythingApplePro. Safari initially plays the five second clip without any problems. However, as the playback progresses, the phone becomes noticeably slower. The full effects aren’t observed until 10-15 seconds after the video ends. The device then comes to a complete standstill, failing to respond to touch input or the home button.
At present, the cause of the bug isn’t clear. The fact it only occurs with one specific video suggests the file may be corrupt. This could create a memory leak in Safari that begins to consume vast amounts of system resources. If improperly handled by iOS, the memory leak would continue indefinitely, crashing the operating system.
While this is the most plausible explanation, there are alternative suggestions. The video itself could be a specially crafted malicious file, including attack code that overwhelms the system. Media files have previously been used to conceal malware. The code is then loaded by the operating system during playback.
Apple is yet to comment on the bug or its cause. It’s almost certainly aware of the widely circulating issue as the clip has gone viral this week. It is being distributed on social media, online forums and in private messaging threads. You should think twice before opening an MP4 file on your iPhone if you don’t want to reboot.
If you are affected by the issue, you can restore your device to health by long-pressing the home and power buttons simultaneously. On the iPhone 7, it’s the power and volume down keys that need to be pressed. The phone will reboot and operate as normal, as long as the video isn’t viewed again. The file does not appear to have any long-term effects and the iPhone should run at its regular speed.
The bug is the third problem to hit Apple devices this month. In the past week, the company has announced a new service option for iPhones with “Touch Disease,” repairing devices for $149. Apple has also launched a battery replacement program for iPhone 6s handsets that could unexpectedly shut down and misreport their charge capacity. It’s now likely to be working on a fix for the MP4 file for release in the next few days.
