The AppleInsider site (not part of Apple) is reporting that Apple says about 400 iTunes accounts were involved Sunday when a Vietnamese developer’s applications were pushed to the top levels in the Apple App Store by fraudulent credit card purchases.

Developer Thuat Nguyen was banned from the store and his applications removed.

Observers believe that the victims’ credit card information was stolen, possibly by phishing, then used to make the fraudulent purchases. Apple has said its systems were not hacked.

Apple said App Store users should check their iTunes and credit card accounts for evidence of fraudulent transactions. The company also said it was ramping up security procedures.

Story here: “Only 400 iTunes accounts compromised in fraud, Apple says”

On Sunday, AppleInsider reported: “Apple’s iTunes Store users are increasingly being targeted in a number of fraud cases, some of which appear to be orchestrated by iOS app developers seeking to boost their sales rankings, and others which appear to be a widespread hack of user accounts.”

“The books in question are a low-quality series of mostly Japanese manga titles all published by ‘developer’ Thuat Nguyen, whose publishing company is listed by Apple as “mycompany” with a website of “Home.com.” It’s impossibly unlikely that 80% of the American App Store’s book sales were legitimately dominated by sales of shoddy anime book apps that are not localized, appear to violate intellectual property rights, and were all dumped into the App Store at once over a period of a couple days.”

Story here: “iTunes App Store hit by developer and account fraud”