"Based on this new information, we believe XcodeGhost is a very harmful and dangerous malware that has bypassed Apple’s code review and made unprecedented attacks on the iOS ecosystem," a blog post from Palo Alto Networks said. "The techniques used in this attack could be adopted by criminal and espionage focused groups to gain access to iOS devices."
In a statement to ABC News, an Apple representative said the fake code was posted online by "untrusted sources."
"Apple takes security very seriously and iOS is designed to be reliable and secure from the moment you turn on your device. We offer developers the industry’s most advanced tools to create great apps," the statement said.
"A fake version of one of these tools was posted by untrusted sources which may compromise user security from apps that are created with this counterfeit tool. To protect our customers, we’ve removed the apps from the App Store that we know have been created with this counterfeit software and we are working with the developers to make sure they’re using the proper version of Xcode to rebuild their apps."
The discovery of malware in Apple's App Store is unprecedented for the company, which subjects apps to a stringent review process before publishing them in the App Store. It appears hackers exploited the tendency of Chinese developers tend to use Xcode from local servers since it can be faster to download. Using a modified version of Xcode would require developers to disable Apple's security features, the team at Palo Alto Networks said.
It was not immediately clear how many people may have been impacted by the malware ridden apps.