Saudi Arabia's national oil company, Aramco, said on Sunday a cyber attack against it in August which damaged some 30,000 computers was aimed at stopping oil and gas production at the biggest OPEC exporter.
The attack on Saudi Aramco - which supplies a tenth of the world's oil - failed to disrupt production, but was one of the most destructive cyber strikes conducted against a single business.
"The main target in this attack was to stop the flow of oil and gas to local and international markets and thank God they were not able to achieve their goals," said Abdullah al-Saadan, Aramco's vice president for corporate planning, on al-Ekhbariya television. It was the firm's first comments on the apparent aim of the attack.
Aramco and the Saudi Interior Ministry is conducting an investigation into the cyber strike. Interior Ministry spokesman Mansour al-Turki said the attackers were an organised group operating from different countries on four continents.
The attack used a computer virus known as Shamoon which infected workstations on August 15 and the company shut down its main internal network for more than a week.
Turki said that the investigation had not shown any involvement of Aramco employees but he could not give more details as the investigation was not yet complete.
Saudi Arabia's economy is heavily dependent on oil. Export revenues from oil have accounted for 80 to 90 percent of total Saudi revenues and above 40 percent of the country's gross domestic product, according to U.S. data.
Shamoon spread through the company's network and wiped computers' hard drives clean. Saudi Aramco said damage was limited to office computers and did not affect systems software that might hurt technical operations.
Hackers from a group called 'Cutting Sword of Justice' claimed responsibility for the attack, saying their motives were political and that the virus gave them access to documents from Aramco's computers, which they threatened to release. No documents have so far been published.
In a posting on an online bulletin board the day the files were wiped, the group blamed Saudi Arabia for "crimes and atrocities" in several countries, including Syria and Bahrain.
Saudi Arabia sent troops into Bahrain last year to back the Gulf state's rulers, fellow Sunni Muslims, against Shi'ite-led protesters. Riyadh is also sympathetic to mainly Sunni rebels in Syria while Iran backs the Syrian leader Bashar al-Assad, whose Alawite religion is an offshoot of Shi'ite Islam.