Sony has been the victim of another cyberattack -- the PlayStation Network and store was hacked and disabled, reports CNET.

Visitors to the site on Sunday night were met with a message reading "Page Not Found! It's not you. It's the Internet's fault." Gamers also reported online game difficulties.  

According to CNET, Sony has not released details, except to say, "We are currently investigating the root cause for the issue."

The online store for games, TV shows and films seems to be restored and operating without problems.

Lizard Squad, an anonymous individual or group, tweeted late Sunday night claiming responsibility. The tweet read: "PSN Login #offline #LizardSquad."

The hack comes less than a week after Sony announced the 20th anniversary of the PlayStation game system. In addition to designing game consoles and video games, the company owns Sony Pictures movie studio which was attacked by hackers in November. The information stolen included Sony employees' social security numbers, customer passwords and celebrity data.

There has been speculation that the North Korean government hacked Sony in retaliation for the comedy film "The Interview," to be released Dec. 25. The movie's plot is about an assassination attempt against the country's leader, Kim Jong-Un. The North Korea government has previously complained about the movie before the United Nations, but denied responsibility for the cyberattack on Sunday.

Sony Pictures employees have received threatening emails following the infiltration of the company's computer network, the FBI confirmed Friday. "We're not confirming the details of the threat," the FBI said in a statement.

Variety reports that the emailed threats read: "Many things beyond imagination will happen at many places of the world ... Please sign your name to object the false of the company at the email address below if you don't want to suffer damage. If you don't, not only you but your family will be in danger."