Sony Pictures declines to reveal progress made fixing hacking Sony Pictures Entertainment is trying to restore its computer systems, five days after hackers claimed to have obtained "top secrets" from the company behind The Amazing Spider-Man and the recent James Bond films. Sony, the Japanese entertainment and electronics group, declined to reveal what progress it was making with fixing the computer problems at its US unit, which is closed for the Thanksgiving holiday. Computers at Sony Pictures went down on Monday after its employees" computer screens reportedly displayed an image of a red skeleton with the headline "hacked by #GOP," which reports have linked to a group called Guardians of Peace. "We've already warned you and this is just a beginning," the hackers said in the image, which was posted on various blogs and appears to show that they want a ransom. "We've obtained all your internal data including your secrets and top secrets," they claimed, threatening to release data "if you don't obey us." The hackers said that they had obtained a vast trove of data from Sony, including PDF files of passports, visas and other documents belonging to actors such as Angelina Jolie and Cameron Diaz. But security experts said it was possible the hackers were bluffing, and may have only obtained a list of the company's files rather than the actual files themselves. Sony said in a brief statement that it was experiencing "a system disruption" that it was "working diligently to resolve." Company officials declined to provide any further details. Emails sent to Sony Pictures on Friday bounced back with the message: "Our email system is currently experiencing a disruption. Please contact the person you wish to reach via office or mobile phone. The latest incident is not the first time the company has been attacked by hackers. In 2011, its PlayStation Network platform was breached, exposing personal information belonging to more than 100m users. Sony's troubles come after Apple admitted in September that some of its most famous customers" iPhone accounts had been accessed by hackers, prompting an investigation by US law enforcement into the mass leak of intimate photographs of more than 100 celebrities. Apple stressed, however, that its central iCloud systems were not breached in the attack, despite claims made by the hackers. "It's another reminder that all of the technology firms are now exposed to the risk of information leaks," said Yoshihiro Okumura, general manager at Chibagin Asset Management. However, investors appear untroubled by Sony's latest computer problems. Shares in the company have risen nearly 7 per cent this week, following signs that the group's restructuring measures are on track.