Panetta appeared before the House intelligence committee, which was holding a hearing on worldwide threats. The CIA director echoed the concerns of FBI Director Robert Mueller, who said cybersecurity was an increasing concern.
"I don't think there's any question but that this is a real national security threat that we have to pay attention to," Panetta said. "I know there are a lot of aspects to it. The Internet, the cyber-arena is this vastly growing area of information that can be used and abused in a number of ways."
Despite the useful aspects of the Internet, Panetta said, "when it comes to national security, I think this represents the battleground for the future. I've often said that I think the potential for the next Pearl Harbor could very well be a cyberattack. If you have a cyberattack that brings down our power grid system, brings down our financial systems, brings down our government systems, you could paralyze this country. And I think that's a real potential. And that's the thing we have to really pay attention to."
The problem is international, he said.
"Other countries are developing a significant capacity in this area, whether it's Russia or China or Iran," Panetta told the panel. "We're now the subject of literally hundreds of thousands of attacks that come in, in an effort to try to get information.
"We've got to develop not only defenses against that," he added, "but we've got to put our assets in places where we can provide sufficient warning that these attacks are coming."
Notable deaths of 2014 [PHOTOS]