The U.S. is investigating potential cyberattacks on oil and gas tankers, as concerns grow around the threat to maritime safety posed by hackers interfering with vessels’ electronic systems.

Personnel from the U.S. Coast Guard and the Federal Bureau of Investigation boarded an unnamed, foreign-flagged vessel on August 21, following indications its network had been compromised by hackers, a Coast Guard spokesperson said in response to questions from Bloomberg News about the VL Prosperity supertanker. 

The VL Prosperity is currently idling off the Texas coast after arriving in the area in late August, ship-tracking data shows. Iran’s semi-official Mehr News Agency reported late last month that the ship, which had picked up oil in Egypt, had its communications cut for 30 hours following a cyberattack in the Strait of Gibraltar.

The tanker has been cleared by the Coast Guard for normal operations, HMM Ocean Service, a South Korea-based company that acts as the safety and technical manager of the ship, said in an emailed response to questions. HMM Ocean Service has rigorous cyber protocols in place to ensure the safety and security of vessels under its care, the company said, adding that it’s awaiting a final investigation report from U.S. authorities.

The VL Prosperity had picked up a crude cargo from Egypt's Sidi Kerir in late July, and reached the U.S. Gulf in late August.

A second vessel, an unidentified liquefied natural gas carrier, was also inspected over a potential cyberattack, according to a Wall Street Journal report that cited an FBI statement. The second boarding occurred on August 24, according to the newspaper.

The incidents come as global shipping comes under increasing strain due to wars and geopolitical rivalry, while vessel owners look to digitize navigational and operating systems in order to optimize journeys and reduce costs. Ships nowadays face myriad security threats, including becoming collateral damage in conflict zones when militaries jam navigational systems in order to foil drone attacks.

“The attack surface for vessels is growing,” said Mark Douglas, an analyst at Starboard Maritime Intelligence, who is also a former New Zealand naval officer. “Vessels’ electronic control systems are increasingly connected to the internet in order to collect data on vessel operations.”

The improvement in ships’ navigational systems makes monitoring their movements and optimizing sailing speeds to save fuel or reduce idling times easier. Yet, it also makes them more vulnerable to hackers, who can infiltrate systems, and dictate anything from a vessel’s ability to navigate to how secure its cargo is.

Cyberattack Guidelines

In April, the U.S. Department of Transportation’s Maritime Administration issued an advisory urging shipowners and operators to adopt best practices to restrict access to these digital systems and reduce vulnerabilities. Last year, the International Maritime Organization, a United Nations agency, issued guidelines on how to manage cyber risks.

Experts boarded the VL Prosperity to “conduct a comprehensive cyber security boarding and investigation,” a Coast Guard spokesperson said. The tanker’s captain, crew, and shore-based staff cooperated with the investigation, and there are currently no reports of operational disruptions, vessel instability, physical danger to crew or environmental impact, the spokesperson said. 

“The Coast Guard is actively managing communications with port operators, vessel owners and local maritime stakeholders to ensure port operations continue safely and without interruption,” the agency said. 

The VLCC had arrived at Sidi Kerir on Egypt’s Mediterranean coast in late July, where it received nearly 2 million barrels of Saudi Arabian oil, ship-tracking data show. It then sailed west, past Gibraltar and into the Atlantic Ocean. The ship’s owner is listed as GMF GLV No. 4 SA, based in Liberia. Maritime database Equasis doesn’t list any telephone or email details for the company.