Applehas placed its developer site under maintenance and confirmed that it had been hacked on July 18.
The hacker had attempted to steal personal information, including developer "names, mailing addresses and/or email addresses" according to Apple in a note posted on the site.
The Cuperitno-based tech giant said that it took the site down immediately after the breach was found on Thursday and that it has been working "around the clock" to fix it since then.
Earlier this year, Apple confirmed that Mac computers on its own network had been targeted by hackers.
While Apple said that all personal information on the developer site was encrypted, it cannot rule out that the hacker was not able to access it.
"In order to prevent a security threat like this from happening again, we're completely overhauling our developer systems, updating our server software, and rebuilding our entire database," it said.
For developers that were to have program membership expire while the system is down, Apple said that memberships have "been extended and your app will remain on the App Store".
Apple hasn't said when exactly the site will be up and running again or if it will be able to determine exactly what data was accessed. And as the breach comes while the company is readying the release of iOS 7, it could potentially push back app development for its new OS.