The hackers behind the massive breach of Sony Pictures’ computer systems last month had sent an extortion email to top company executives three days before launching the cyberattack. The communication was among several corporate emails leaked by the self-proclaimed hackers group “Guardians of Peace,” or GOP, on Monday.

The email, which was sent on Nov. 21, was addressed to Sony Pictures CEO Michael Lynton, Chairman Amy Pascal and other senior executives. The email, written in broken English, threatened to do “great damage” to Sony if the company failed to pay “monetary compensation.”

“Pay the damage, or Sony Pictures will be bombarded as a whole. You know us very well. We never wait long. You'd better behave wisely,” the hackers said in the email, which was titled “Notice to Sony Pictures Entertainment.”

The email was sent from a Gmail account registered under the name “Frank David,” Computer World reported, adding that the IP address of the sender could not be identified as the hackers appeared to have used Gmail's Web interface to compose the message.

The extortion email was signed “God'sApstls,” which was found inside some of the malware used to hack Sony on Nov. 24.

While the newly discovered email suggests that the hackers attacked Sony with a financial motive, it is still not clear if they had communicated with the company previously or had set a specific dollar amount for their demands. The email does not make any reference to North Korea or the movie “The Interview,” which was part of a growing theory that Sony was hacked in a North Korea-funded protest against the satirical movie about a plot to assassinate Kim Jong-un.

On Monday, however, GOP hackers warned Sony not to release the movie, and demanded that the studio “stop immediately showing the movie of terrorism which can break the regional peace and cause the war!”

In latest Sony hack Pastebin hackers again talk about unmet demands and deny responsibility for threatening emails.

— Lorenzo Franceschi B (@lorenzoFB) December 8, 2014

Although North Korea has praised the hack as a “righteous deed” against U.S. imperialism, the country has also denied allegations that it had backed the hackers.