(Sharecast News) - Apple has reportedly sent threat notifications to iPhone users in 92 countries who may have been victims of a "mercenary spyware attack".

According to numerous news outlets in India, a notification email sent by the tech giant to customers said that attackers have attempted to "remotely compromise the iPhone associated with your Apple ID".

It is unclear how many iPhone users have been targeted by the attacks, but the security notice on Apple's website says the vast majority of users will never be targeted by such attacks.

"Apple threat notifications are designed to inform and assist users who may have been individually targeted by mercenary spyware attacks, likely because of who they are or what they do," the security notice on Apple's website said.

"Such attacks are vastly more complex than regular cybercriminal activity and consumer malware, as mercenary spyware attackers apply exceptional resources to target a very small number of specific individuals and their devices."

Apple said that the cost, sophistication and global nature of mercenary spyware attacks "makes them some of the most advanced digital threats in existence today".