Palo Alto Networks:

We’ve discovered a new family of iOS malware that successfully infected non-jailbroken devices we’ve named “AceDeceiver”.
What makes AceDeceiver different from previous iOS malware is that instead of abusing enterprise certificates as some iOS malware has over the past two years, AceDeceiver manages to install itself without any enterprise certificate at all. It does so by exploiting design flaws in Apple’s DRM mechanism, and even as Apple has removed AceDeceiver from App Store, it may still spread thanks to a novel attack vector.

And (boldface mine):

Three different iOS apps in the AceDeceiver family were uploaded to the official App Store between July 2015 and February 2016, and all of them claimed to be wallpaper apps. These apps successfully bypassed Apple’s code review at least seven times (including the first time each was uploaded and then four rounds of code updates, which require an additional review by Apple for each instance) using a method similar to that used by ZergHelper, where the app tailors its behavior based on the physical geographic region in which it’s being executed. In this case, AceDeceiver only displays malicious behaviors when a user is located in China, but that would be easy for the attacker to change in any time. Apple removed these three apps from the App Store after we reported them in late February 2016. However, the attack is still viable because the FairPlay MITM attack only requires these apps to have been available in the App Store once. As long as an attacker could get a copy of authorization from Apple, the attack doesn’t require current App Store availability to spread those apps.

Looks like this attack is currently restricted to users in mainland China.