The attempts took place between October 7 and 10 and succeeded in verifying valid sign-in IDs and passwords of about 93,000 accounts on its PlayStation Network, Sony Entertainment Network and Sony Online Entertainment services.
Sony said credit card details associated with those accounts were not at risk as a result of the attempts.
Sony has temporarily locked these accounts and is continuing investigations into the extent of unauthorised activity. It said it would notify affected account holders to advise them to reset their passwords.
The entertainment giant has been battling to restore consumer trust after a data breach in April compromised more than 100 million online accounts, forcing it to temporarily shut down its PlayStation Network and Qriocity music services.
Analysts say such breaches threaten to further damage Sony's brand image and undermine its efforts to link its gadgets to an online "cloud-based" network of games, movies and music that relies on consumer confidence in their security. (AFP)