Apple is involved in a massive clean-up of its iOS App Store to remove malicious software which has infected numerous iPhone and iPad programmes, according to reports.
The malware, dubbed XcodeGhost, was discovered by several cyber security companies which found it embedded in hundreds of legitimate apps, the Reuters news agency said.
It is the first reported case of large numbers of malicious software programmes making their way past Apple's stringent app review process.
Before this attack, just five malicious apps had ever been found in the App Store, according to Palo Alto Networks Inc.
The hackers embedded the malicious code in these apps by convincing developers of legitimate software to use a tainted, counterfeit version of Apple's software for creating iOS and Mac apps, which is known as Xcode, Apple said.
"We’ve removed the apps from the App Store that we know have been created with this counterfeit software," an Apple spokeswoman said in an email to Reuters.
"We are working with the developers to make sure they’re using the proper version of Xcode to rebuild their apps."