Mashable - Apple has a reputation for being virus and malware-free, but a hacker has uncovered a potentially dangerous security flaw in the App Store. Charlie Miller, a Mac hacker and computer security researcher, has made a bit of a career finding and exposing flaws in Apple's software. His latest discovery shows how the App Store, Apple's tightly regulated marketplace for iOS apps and programs, could be compromised by code not approved by Apple, reports Forbes.