Apple removes malware-infected apps from App Store

Apple Inc. has removed some applications from its App Store after developers in China were tricked into using software tools that added malicious code in an unusual security breach.

Apple gave no details of which companies were affected. But Tencent Ltd. said its popular WeChat app was affected and the company released a new version after spotting the malicious code. Chinese news reports said others affected included banks, an airline and a popular music service.

Palo Alto Networks, a U.S.-based security firm, analyzed the malware and found 39 infected iOS apps, "some of which are extremely popular in China and in other countries around the world, comprising hundreds of millions users."

The malicious code spread through a counterfeit version of Apple's Xcode tools used to create apps for its iPhones and iPads, according to the company. It said the counterfeit tools spread when developers obtained them from "untrusted sources" rather than directly from the company.

An Apple spokeswoman told CNET, "We've removed the apps from the App Store that we know have been created with this counterfeit software. We are working with the developers to make sure they're using the proper version of Xcode to rebuild their apps."

The malicious software collects information from infected devices and uploads it to outside servers, according to Palo Alto Networks.

It was first publicized last week by security researchers at Alibaba Group, the e-commerce giant, who dubbed it XcodeGhost.

The creators of the malware took advantage of public frustration with Beijing's Internet filters, which hamper access to Apple and other foreign websites. That prompts some people to use copies of foreign software or documents that are posted on websites within China to speed up access.

"Sometimes network speeds are very slow when downloading large files from Apple's servers," wrote Claud Xiao, a Palo Alto Networks researcher, on its website. Due to the large size of the Xcode file, "some Chinese developers choose to download the package from other sources or get copies from colleagues."

Companies with apps that were affected include taxi-hailing service Didi Kuaidi, Citic Industrial Bank, China Southern Airlines and the music service of NetEase, a popular Web portal, according to the newspaper Yangcheng Evening News.

The incident is the only the sixth time malicious software is known to have made it through Apple's screening process for products on its App Store, according to Xiao.

Last week, Apple released iOS 9, the latest version of its mobile operating system for iPhone, iPad and iPod Touch. On Monday, it said that more than 50 percent of those devices had already been upgraded to iOS 9, CNET reported.