A Brazilian aerospace conglomerate Embraer S.A revealed Monday it has suffered a cyber attack on its IT-systems, which may led to “the disclosure of data.”

According to the company, the incident took place on November 25, 2020 and impacted “only company’s archive environment.”

While the aircraft manufacturer has not revealed the nature of the cyber attack or what kind of data might have been stolen, people familiar with the matter told the Brazilian newspaper O Globo that due to the incident Embraer had to shut down a good part of its servers and that the intruders got access to some of its backup systems.

The attack also temporarily affected access to company’s systems for staff that had been working from home. At the time the company's IT team told employees it was a system glitch, not a hacker attack, said Globo.

According to the sources the attackers demanded a ransom in cryptocurrency from the company, which suggests that Embraer had become a victim of a ransomware attack.

In the notification letter Embraer said that it continues to operate “with the use of some systems in a contingency regime, without significant impacts on its activities” and that “it is making all its efforts to investigate the circumstances of the attack, assess whether there are impacts on its business and third parties, and determine the measures to be taken.”