The network used by PlayStation 3 owners to purchase and play games online, as well as access other Internet-based services, has been disabled since Wednesday.
The company has not stated whether any personal data including credit card numbers has been compromised, USA Today reported Sunday.
"Though this task is time-consuming, we decided it was worth the time necessary to provide the system with additional security," Patrick Seybold, a Sony official, said in a recent statement. "We sincerely regret that PlayStation Network and Qriocity services have been suspended, and we are working around the clock to bring them both back online."
Seybold did not say when the network would be fully restored.