The group responsible for the catastrophic hack of Sony Pictures warned executives at the company three days before carrying out its attack, according to email evidence discovered by Mashable among the leaked material. This email was reportedly sent to CEO Michael Lynton and chairman Amy Pascal, among others:

We've got great damage by Sony Pictures.

The compensation for it, monetary compensation we want.

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.

From God'sApstls

Mashable found the email inside files from the account of Pascal, who apparently didn't read the message. It's signed "God'sApstls," a term said to have appeared in malware used in the initial attack on Sony Pictures' systems on November 24th.

Although the perpetrators of the hack are still unknown, some evidence suggests that the incident may be linked to North Korea. The secretive state has expressed outrage over The Interview, a Sony Pictures movie centered around a plot to assassinate DPRK leader Kim Jong-un. This email's non-native English and apparent sense of having been wronged by Sony Pictures could further point to a connection with the country, which is known to employ thousands of hackers.