Sony has told employees to avoid connecting to corporate networks or access their email accounts after the media conglomerate said it was hit Monday by a malicious hacker attack, where someone threatened to disclose "secrets" about the company.

According to a source within Sony, the company is telling its employees that the situation could take anywhere between a day to three weeks to resolve. The source claimed a photo appeared on many company computer screens Monday morning with a skeleton image and cryptic message displayed.

"Hacked by #GOP," the message read according to Variety. "Warning: We've already warned you, and this is just the beginning...We have obtained all your internal data including secrets and top secrets."

It isn't clear at this point which individual or groups were responsible for the attack, or specifically what the goal of the hacker's digital break-in were.

Sony's information-technology departments instructed workers that they should turn off their computers and disable Wi-Fi on their mobile devices.

"We are down, completely paralyzed" another source at Sony told Deadline.com.

The "Hacked by #GOP" message went on to warn that the data they supposedly confiscated from Sony's systems would be revealed Monday at 6 p.m. Eastern time, but there is no word when or where this unveiling would take place. Whatever group is behind the attack did not make any specific demands against Sony.

Back in August, hackers claimed that they had broken into Sony's PlayStation Network through a denial-of-service attack, which basically overtakes the gaming system with false network requests. However, Sony said after the attack that no personal data of any of PlayStation Network's 53 million users was compromised on Aug. 24. Access to the network was restored the following day.

In 2011, PlayStation Network customers' names and passwords were exposed in another attempt at hacking into the network.

Sony spokesperson Jean Guerin simply told Deadline.com that "we are investigating an IT matter."