China's "Great Firewall" may have been partly to blame for the first major attack on Apple Inc.'s App Store, but experts also point the finger at lax security at some big-name Chinese tech firms and at how Apple supports developers in its second-biggest market.

A malicious program, dubbed "XcodeGhost," hit hundreds — possibly thousands — of Apple iOS apps, including products that are made by some of China's most successful tech companies and are used by hundreds of millions of people.

Palo Alto Networks, the U.S. Internet security company that spotted the problem, says the attacker could send commands to infected devices that could be used to steal personal information and, in theory, conduct phishing attacks.