The hackers behind a devastating cyberattack at Sony Pictures have sent a new message to executives at the company, crediting them for a "very wise" decision to cancel the Christmas day release of "The Interview," a source close to the company told CNN.

The email message was received by Sony's top executives on Thursday night and was obtained by CNN.

The source said that the company believes the email was from the hackers because it followed a pattern of previous messages, sent to a list of particular executives and formatted in a particular way.

A Sony spokesman declined to comment.

Also on Friday, President Obama said he disagreed with Sony's decision.

"I am sympathetic to the concerns that they face. Having said all that, yes I think they made a mistake," Obama said at a White House press conference.

"We cannot have a society where some dictator someplace can impose censorship here in the U.S.," he added.

Related: FBI: North Korea responsible for Sony hack

The FBI has officially linked the cyberattack at Sony to the North Korean government.

"The destructive nature of this attack, coupled with its coercive nature, sets it apart," the FBI said in a statement.

The Motion Picture Association of America called the hack a "despicable, criminal act" on Friday.

"This situation is larger than a movie's release or the contents of someone's private emails," said Chris Dodd, CEO of the lobbying group. "This is about the fact that criminals were able to hack in and steal what has now been identified as many times the volume of all of the printed material in the Library of Congress."

The hacker message is effectively a victory lap, telling the studio, "Now we want you never let the movie released, distributed or leaked in any form of, for instance, DVD or piracy."

The message also says, "And we want everything related to the movie, including its trailers, as well as its full version down from any website hosting them immediately."

It warns the studio executives that "we still have your private and sensitive data" and claims that they will "ensure the security of your data unless you make additional trouble."

The email was titled "Message from GOP." The anonymous hackers have called themselves "Guardians of Peace."

Sony is still reeling from the late November cyberattack that crippled its computer systems, and now it is under severe scrutiny for canceling the Christmas release of "The Interview," Seth Rogen and James Franco's comedy about an attempted assassination of North Korean leader Kim Jong-un.

U.S. officials now believe North Korea instigated the hack, lending credence to the Sony executives who privately started calling it a "terrorist act" weeks ago.

Since the cancellation on Wednesday, the same executives have been wondering whether the leaks of private emails and corporate documents would now stop.

Thursday night's message implied that the leaks will stop.

In a statement on Wednesday when the film's release was scrapped, the company said "we stand by our filmmakers and their right to free expression and are extremely disappointed by this outcome."

Many lashed out at the studio for its unprecedented decision to pull the movie. Others have rallied around Sony's predicament.

George Clooney, in an interview with Deadline.com on Thursday, revealed that he had circulated a petition earlier in the week saying "we fully support Sony's decision not to submit to these hackers' demands" -- but no one was willing to sign it.

"It was a large number of people. It was sent to basically the heads of every place," Clooney said without naming names.

The petition said, "This is not just an attack on Sony. It involves every studio, every network, every business and every individual in this country," and it concluded, "We hope these hackers are brought to justice but until they are, we will not stand in fear. We will stand together."

It's outdated now, since Sony did cancel "The Interview." In the interview, Clooney expressed sadness that "as we watched one group be completely vilified, nobody stood up."