Rio Tinto memo says staff data might have been hacked

"Investigations now indicate a possibility that Rio Tinto data may be impacted," it said.

The cybercriminal group threatened to release the data onto the dark web and investigations into the incident were ongoing, the Anglo-Australian mining giant said.

"To date, none of the records described above have been released, and we still do not know if the cybercriminal group holds these records or not."

The stolen data relates to an attack on GoAnywhere - a managed file transfer (MFT) software offered by cybersecurity firm Fortra - which also provides its services to Rio.

As GoAnywhere is a cloud-based vendor, there is no operational impact or risk to the Rio Tinto network, the memo said.