(CNN) — The United States is investigating "a string of malicious" cyber incidents that appear to be focused on probing energy infrastructure, a U.S. official familiar with the latest intelligence tells CNN.
The official, who spoke anonymously due to the sensitivity of the information, said the suspected hacking did not appear to be intended to steal trade secrets or exploit technology for commercial reasons. It appeared to be aimed at identifying weaknesses in fuel and electrical systems in the United States.
While the official did not identify any suspected origins of the apparent hacking, a U.S. lawmaker raised suspicions about Iran.
The United States has over the past year become more concerned about Iran and cyber security.
American officials said last October that cyber attacks on U.S banks and oil companies in Saudi Arabia and Qatar in 2012 were believed to be carried out by surrogates supported by the Iranian government.
Iran denied any involvement.
The United States recently tightened its already tough economic sanctions against Iran in an ongoing bid to make Tehran temper its nuclear ambitions. And Congress just released a report illustrating how vulnerable the electric grid is to potential attacks from Iran and North Korea.
Rep. Adam Schiff, a California Democrat and House Intelligence Committee member, told CNN that the United States has seen "disturbing indications" that Iranian-linked elements appear willing to target U.S. infrastructure via cyber means.
"The Iranians seem less interested in stealing our military secrets or stealing how we're going to make the next Apple product," Schiff said. "They're more interested in probing our vulnerabilities -- our financial structure vulnerabilities, our critical infrastructure vulnerabilities, so they can attack us - literally shut down, manipulate - cause an industrial accident."
He suggested suspected hacking could be the work of the Tehran government, organizations with ties to it like the elite Quds Force, hackers who are subsidized or private entities working on their own.
James Lewis, a senior fellow with the Center for Strategic and International Studies who has advised the White House on cyber issues, said the apparent incidents would indicate a "new kind of vulnerability."
Lewis says Iran could potentially use any such capability as a hedge against future attacks.
"If there is something else that happens in relation to their nuclear program, they have the ability now to do things that are damaging to the U.S.. And we don't really have a good way to stop them," he said.
The Wall Street Journal first reported the latest developments.