Apple keeps 30 percent of the profits on App Store's paid applications, and the developers take 70 percent. [File photo]

A dirty worm has found its way into the core of Apple's App Store software platform. Apple fans are now reporting finding pornographic apps among download rankings. And three of the 100 most popular apps have been suspected of being involved in porn.

Liu, who recently downloaded a collection of ancient Chinese novels from the App Store, said he found it contains lots of racy passages and scandalous affairs.

Apple keeps 30 percent of the profits on App Store's paid applications, and the developers take 70 percent, said an application programmer who declined to give his name.

Apple said it has reviewed all the apps that are available on the App Store, and it insisted that it is possible for users to find out whether applications contain inappropriate content as described in the App Store's terms and conditions.

China's business press carried the story above on Monday.