Iranian hackers breached control systems of a dam near New York City in 2013, the Wall Street Journal has revealed.
According to the newspaper’s sources, the hackers accessed systems of the Bowman Avenue Dam, about 30km from New York City, through a cellular modem.
The breach of the flood-control dam, which is only about 6m tall, was very difficult to track down, the sources said, and investigators originally thought the hackers were aiming at a much larger dam in Oregon.
The breach, believed to be retaliation for claims that American spies damaged an Iranian nuclear facility with the Stuxnet computer worm, has raised concerns over the cyber-defences of the USA's strategic infrastructure.
The attack came at the same time when hackers linked to the Iranian government were targeting US bank websites.
Homeland Security spokesman SY Lee would not confirm the breach to Reuters. He said the department's 24-hour cybersecurity information-sharing hub and an emergency response team coordinate responses to threats to and vulnerabilities in critical infrastructure.
According to the Wall Street Journal, the United States has more than 57,000 industrial control systems connected to the Internet that might be at risk of possible infiltration.