In its response to the YiSpecter malware that is the first-of-its kind affecting both jailbroken and non-jailbroken iOS devices, Apple said it has already patched the security flaw in iOS 8.4 version. It further warns users to download apps from App Store only, and not from any suspect sources to avoid such malicious software attacks.

"This issue only impacts users on older versions of iOS who have also downloaded malware from untrusted sources. We addressed this specific issue in iOS 8.4 and we have also blocked the identified apps that distribute this malware. We encourage customers to stay current with the latest version of iOS for the latest security updates. We also encourage them to only download from trusted sources, like the App Store, and pay attention to any warnings as they download apps," notes Apple in an official statement issued to The Loop.

Apple's response comes just a day after Cyber security firm, Palo Alto Networks announced the discovery of YiSpecter that so far affects iOS users in China and Taiwan. Even Palo Alto advised not to download apps from untrusted sites. It has released IPS signatures to detect and block malicious command and control (C2) traffic related to YiSpecters.

The firm has also redesigned signatures to detect the queries for the C2 domains used by the malware that is said to have been in the wild for more than 10 months. Palo Alto speculates the malware is developed by YingMob Interaction, whose official site suggests that it is a Chinese mobile advertisement platform.