Below, we published a link to the "Safari Killer" - a page that launches malicious code and causes the browser to hang, and then forcibly reboot the entire device. Some our friends send this link for our friends. :) We think that this is not necessary. This link is only for testing and experiments to find a solution.
The new iOS 12 bug does not cause serious problems, however we do not recommend you to experiment with your own iPhone or iPad.
The malicious code responds to Apple's smartphones and tablets that run on iOS 7 or later. The bug is present even in the latest builds of firmware, iOS 11 and iOS 12.
Unlike other malicious links that are triggered by clicking in iMessage, this needs to open an application capable of running HTML code. In other words, the device will force reboot if you go directly to a malicious page in Safari or if the developer embeds the code in the body of the email.
iOS 12 - Don't install this App on iPhone running on iOS 12.