The firm has warned that those found to be using unauthorised or pirated software will have their PSN accounts permanently disabled.
Sony said in a statement: "Unauthorized software for the PlayStation 3 system was recently released by hackers.
"Use of such software violates the terms of the System Software License Agreement for the PlayStation 3 System and the Terms of Services and User Agreement for the PlayStation Network/Sony Entertainment Network and its Community Code of Conduct provisions.
"Violation of the System Software License Agreement for the PlayStation3 system invalidates the consumer's right to access that system.
"Consumers running unauthorized or pirated software may have their access to the PlayStation Network and access to Sony Entertainment Network services through PlayStation 3 system terminated permanently.
"To avoid permanent termination, consumers must immediately cease using and delete all unauthorized or pirated software from their PlayStation 3 systems."
Sony added that it's taking these steps to "help provide a safe, fair, online environment" for consumers.