Apple's fixed a security hole which could reportedly allow iPhones to be infected with spyware without any user action.
Researchers say it was used on a phone belonging to a Saudi activist.
It's thought to be the first time a so-called 'zero-click' exploit has been caught and analysed.
All major Apple devices were vulnerable to the flaw.
Apple users are being advised to update their software immediately after the company was notified of a security flaw.
Affecting the iPhone, iPad, Mac and Smart Watch products, it reportedly allowed them to be exploited by spyware.
The tool, called Pegasus, is said to be able to open and copy text messages, videos, photos and web activity including passwords.
Many will be waking up this morning with the i-O-S 14.8 software automatically downloaded.