A recent attack against Saudi Aramco damaged the world’s largest oil producer and delayed oil production, roiling oil and gas markets. The Saudi government and U.S. intelligence officials have claimed the incident is the work of Iran, while Iran blamed Yemeni rebels.

This is a real-world continuation of a long-simmering cyberwar between the two countries, which has spilled over into other global powers.

In recent years, Iran has deployed destructive computer viruses against Saudi Arabia. The Kingdom and oil and gas industry have been slow to shore up their defenses, raising red flags about the possibility of longer term fal-out in the region, experts said. Investors should expect long-term cyber espionage and flare-ups of malicious activity, including the potential for destructive attacks that hurt companies in the region beyond Aramco.

Saudi Aramco declined to comment for this article.