The crisis in the NSA caused by a massive hacker attack has decreased the morale of its employees, with many of them reportedly preferring to leave the agency for better-paid jobs.

According to the New York Times, the US National Security Agency (NSA) has been deeply shaken by a massive infiltration that resulted in the theft of cyberweapons by unidentified hackers.

Last year, the Shadow Brokers hacking group obtained a number of NSA tools to spy on other countries and issued actual codes for some of these tools. Those responsible for the massive security breach have not been found yet.

READ MORE: Who is NSA Whistleblower Bill Binney, Dragged By MSM as ‘Conspiracy Theorist’?

According to The New York Times, the hacking incident had catastrophic consequences for the National Security Agency, calling into question its ability to protect cyberweapons and even its value for US national security.

“The fundamental purpose of intelligence is to be able to effectively penetrate our adversaries in order to gather vital intelligence. By its very nature, that only works if secrecy is maintained and our codes are protected,” Leon Panetta, the former defense secretary and director of the Central Intelligence Agency, was quoted as saying by the newspaper.

The 15-month investigation reportedly failed to reveal whether the security breach was caused by a hacking operation, by an insider’s leak, or both. Three people have been arrested since 2015 for taking classified files but it is not clear whether they were involved in the incident that is being described by many experts as more harmful than the disclosures made by former NSA contractor Edward Snowden.

The New York Times said that Russia was likely behind the leak of NSA classified information, without giving any specific evidence.

Last summer, many companies around the world were attacked by virus-encryptors WannaCry and Petya. Many experts believe that the recent wave of ransomware attacks were staged with the use of the leaked NSA codes.