Apple said Tuesday it is aware of "intermittent organized network attacks" on users attempting to sign in on iCloud.com, according to Dow Jones.
However, the company said iCloud servers were not compromised. Apple added that the attempted attacks don't affect iCloud sign-in on mobile and Macs that are running the most up to date version of OS X.
Apple's disclosure about the iCloud attacks did not mention China, according to Dow Jones.
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Earlier, a Chinese Web monitoring group said hackers tried to steal user credentials on iCloud's storage and backup service in China. The Chinese nonprofit watchdog site, Greatfire.org, alleged that Chinese government authorities may have been involved in the attacks.
The attack used a "man-in-the-middle" tactic, in which hackers intercept a user's online communication with iCloud without letting the user know.
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