"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,
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