"Starting September 18, Apple began to remove some iOS apps infected by XcodeGhost from its App Store.... As of this writing, on Monday, September 21, we notice that there are still some previously known infected iOS apps available in App Store."
> As you said, a binary grep, coupled with many of Apple's static/dynamic analysis tools should be enough to find this issue.
As I said, it should be so simple if Apple had set up the basic infrastructure for this. Since it had not, Xcodeghost remained on the App Store long after it was initially discovered, allowing researchers to find thousands more affected apps. Compare to Google's Play Store which not only performs static analysis but also crash analysis, battery usage analysis, and dynamic analysis through running the apps in cloud VMs (something Amazon did at launch).
Where does the link say this? As far as I know Apple has all the information needed to make this decision themselves. As you said, a binary grep, coupled with many of Apple's static/dynamic analysis tools should be enough to find this issue.