JBS American Food Processing Inc. (JBS) said on Monday that it had been hacked into information systems in North America and Australia, shutting down some of its plants and affecting thousands of Australian workers.

In a statement, JBS America said it discovered the hacking of its information systems on May 30 and confirmed that it had been "the target of an organized cyber attack that affected some of the servers that support information systems in North America and Australia." The company shut down all of its computer networks, notified government agencies, called in information engineers and "third-party experts to respond." However, the company's "backup servers were not affected" and it was "actively working with a cyber security firm to restore the system as soon as possible."

"The company is not aware of any evidence that customer, supplier or employee data has been compromised or misused as a result of the current situation," the statement said. Resolving the issue will take time and may delay some of the company's transactions with customers and suppliers."

There have been no reports of any disruption to U.S. operations, Bloomberg News reported Monday. But the attack halted operations at one of the company's large beef processing plants in Canada. According to one job AD, the plant handles about 4, 200 head of beef cattle a day, accounting for more than a quarter of Canada's national production.

The attack also crippled facilities in Australia owned by JBS US food processing company, forcing as many as 10,000 meat company workers to shut down, Agence France-Presse reported, citing an Australian union representative.

The Beef Hub, an online news site for the Australian beef industry, quoted Brent Eastwood, chief executive officer of JBS US food processing company Australia, as saying the attack had targeted corporate information systems. Cattle and sheep slaughter plans across Australia have been cancelled and workers have gone home after a cyber attack.

JBS Foods USA operates 47 plants across Australia and has the largest meat processing and breeding network in the country, according to the Australian Broadcasting Corporation.

JBS American Food Processing, headquartered in Greeley, Colorado, USA, is a wholly owned subsidiary of JBS GMBH, headquartered in Brazil. It is the first US company to be hacked in the past month, but it is not yet clear who was involved or for what purpose.

Due to a hacker attack, a major oil line of the U.S. Colonial Pipeline Transportation Company was suspended from May 7, but initially restarted on the afternoon of May 12, and the whole line was resumed on May 13. At one point, the company was forced to shut down its entire energy supply network, significantly affecting fuel supplies along the East Coast of the United States.

Hackers use encryption to lock up corporate computer systems and steal confidential files, demanding a ransom in exchange for the unlock. The FBI has named the hacking group "The Dark Side" for the attack.