The intrusion last Thursday marked a rare cyberattack on the U.S. company's network.
Apple Inc.'s main website for developers remains shut after intruders tried to steal sensitive information last week, forcing the iPhone maker to overhaul its database and server software to prevent future breaches.
The intrusion last Thursday marked a rare cyberattack on the U.S. company's network and comes at a time when third-party developers are testing their apps on Apple's iOS 7 — a smartphone and tablet platform to be launched in the fall.
Apple's developer site also houses sensitive financial information, which is encrypted.
Apple said on Sunday that no customer information had been compromised, but was unable to rule out the possibility that some developers' names, mailing addresses and email addresses may have been accessed.
An Apple spokesman said the website that was breached was not associated with any customer information.
It remained unclear how much, if any, data was compromised or who the attackers were. Apple would not comment on their identity.
"Sensitive personal information was encrypted and cannot be accessed. However, we have not been able to rule out the possibility that some developers' names, mailing addresses and/or email addresses may have been accessed," Apple told developers on its website.
"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," Apple said in a statement, adding that the developer website will be up and running soon.
The company also told developers that their membership, if set to expire, has been extended, and all third-party apps will remain on Apple's app store for the duration.