'US fin institutions under hackers' attack'

American financial institutions are 'actively under attack' from hackers, a top Obama Administration official has said.

"Right now financial institutions are actively under attack. We know that," the Secretary of Homeland Security, Janet Napolitano, said on Wednesday responding to a question at The Washington Post Live 2012 Cyber security Summit in Washington.

Without going into details of such cyber-attack, Napolitano said this has involved some of the US's largest institutions.

"We've also had our stock exchanges attacked over the last years. So I mean, we know they're there. There are vulnerabilities," she said.

"I really don't want to go into that per se.

"All I want to say is that there are active matters going on with financial institutions.

"The energy sector is a concern for us because of what has happened in other places in the world," she said.

"But when you look at cyber in terms of infrastructure,

we have actually divided the nation's core critical infrastructure into sectors," she added.

Observing that the nation is under attack constantly on cyber, she said it is an area that she has seen grow in sophistication and number in the almost four years that she has headed this office.

"One of the possible areas of attack, of course, is attacks on our nation's control systems, the control systems that operate our utilities, our water plants, our pipelines, our financial institutions.

"If you think that a control system attack that takes down a utility even for a few hours is not serious, just look at what is happening now that Mother Nature has taken out those utilities.

"The cascading effects are immediate, they are serious, and they can be life-threatening," she said.

"So the urgency, the immediacy of the cyber problem, the cyber-attacks that we are undergoing and continue to undergo cannot be overestimated," she said.

"We have and are undergoing attacks on some of the largest financial institutions in the United States today," she added.