Saudi Aramco, based in Dhahran in Saudi Arabia's eastern province, has the world's biggest daily oil production and pulled in revenue of US$229.9 billion (A$312.27 billion) in 2020.
In response to a query from iTWire, a company spokesperson said it recently became aware of the indirect release of a limited amount of company data.
"We confirm that the release of data was not due to a breach of our systems, has no impact on our operations, and the company continues to maintain a robust cyber security posture,” the spokesperson added.
Screenshots of some of the documents on offer were posted on the Web, including what are claimed to be details of the oil pipeline between Saudi Arabia and Bahrain.
In another post, this time on the dark web, the seller sought US$50 million in the monero cryptocurrency in exchange for selling and also wiping the data. A sale alone was priced at about US$3.4 million in monero based on the current value of the cryptocurrency.
In 2017, Saudi Aramco suffered a malware intrusion with a safety system coming under attack. This was claimed to be the first case of malicious code being used to target a system designed to prevent disaster at an industrial facility.
This attack was detailed by American security company FireEye which did not reveal the company's name.
At that time, Saudi Aramco was preparing for an IPO, part of a move by the country's crown prince, Mohammed bin Salman, to raise funds for an ambitious modernisation plan.
According to Wikipedia, Saudi Aramco suffered a virus attack in August 2012 which it said no computers involved in oil production were affected.