Apple's Developer Center site is currently offline with a warning issued to developers about "an intruder attempted to secure personal information" of registered developers, according to a statement on its official website.
"Last Thursday, an intruder attempted to secure personal information of our registered developers from our developer website," the announcement states. "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."
As a result of the attempt, the website was taken offline on July 18. Apple is currently overhauling the developer systems, updating server software and rebuilding the entire database.