This is a rush transcript from "On the Record," July 8, 2009. This copy may not be in its final form and may be updated.

GRETA VAN SUSTEREN, FOX NEWS HOST: Since early April, North Korea has conducted an underground nuclear test and has been firing missiles towards the United States. But it has been more than just tests. North Korea has also threatened an attack.

But has the communist nation already begun its attack on the United States? Dozens of Web sites in the United States and South Korea, including US government sites, have been targets of cyber attacks in the past week.

A senior defense official tells FOX News that the attacks originated from North Korea. Joining us is Rod Beckstrom, former Department of Homeland Security cyber chief.

Good evening, Rod. Rod, do you have any idea what this attack might be, this cyber attack, and the impact?

ROD BECKSTROM, FORMER DHS CYBER CHIEF: Sure. This attacked is a bot- net attack. It looks like it took place in South Korea, the machines there.

It may have been sponsored in North Korea, which is what some people are expecting -- infested some are in the tens of thousands of machines and started hitting all the U.S. government Web sites and key government Web sites in Korea with a lot of requests, up to 100,000 Internet requests per second, overloading their systems.

Sort of like jamming your own personal mailbox with 100,000 letters in hour is a bit of a problem. That kind go helps you visualize the problem here.

VAN SUSTEREN: Is this a nuisance, I mean, just an incredible nuisance, or is this truly destructive? And also, has it harmed our national security?

BECKSTROM: It is more of a nuisance. This is more in the graffiti school of cyber attacks, you know, someone trying to paint nasty messages, break through some windows, and kind of make a mess. It is more of a political statement.

To my knowledge, no compromise of national systems in terms of data taken out and taken back somewhere else, just really annoying behavior and actions meant to probably send a political message by whoever sponsored it.

VAN SUSTEREN: Getting information is one thing, and getting data, which you said didn't happen, but could in any way sort of impeding any of our communication, which could have a national security impact?

BECKSTROM: Sure. Well, you know, it did fit the Department of Treasury systems pretty hard today, is my understanding. And for a while at least, legitimate parties coming in from outside were having a hard time getting in through all that noise and all that falcon of all those false messages.

So treasure is a vital U.S. national asset, so, yes. And in Korea, there may have been some of the same experiences.

VAN SUSTEREN: Why would the Pentagon think it is North Korea? Can they actually track it down?

BECKSTROM: If they could find who wrote the check to get this started, or who wrote the code and dropped it on a machine, then they can know for sure. It's pretty difficult usually to precisely attribute these things.

But if you look at the behavior over the last week, you know, it is a pretty good guess that it might be coming from that direction. They may have done the digital forensic and found the digital fingerprints to track all the way back there, or they may have other sources of intelligence that I'm certainly not aware of.

But, certainly, people are questioning North Korea in this issue.

VAN SUSTEREN: It sounds so sinister when we think that it might be North Korea, that they're sitting around and possibly jamming our computers and doing something to our government computers.

On the other hand, could this be a guy or a woman who is sitting someplace in front of a keyboard who did this?

BECKSTROM: You know, it actually could be. This specific type of attack is an old technology from 2004 that's been tuned up a bit. We found fragments of code that the programmer created that has been spread around. It will start being blocked by anti-virus. So it's not a particularly sophisticated attack.

It could have been done by a single individual that personally was motivated politically, or someone dropped them $10,000 check or a $50,000 check or something else, and said, "Go, get this done, and cover your tracks."

VAN SUSTEREN: How about someone who just thought, gee, this would be fun, and not realize that this is really serious.

BECKSTROM: It doesn't look like an accident. Those accidents do happen sometimes when teenagers are playing around with writing code and seeing if they can create some little virus for fun or something.

But in this case, because it's so specifically targeted at a number of South Korean government Web sites, business Web sites, U.S. government Web sites and business sites, it looks very well targeted. So there seems to be a political message behind this, a little bit like launching some scud missiles towards the U.S. These are cyber scuds, very low-tech, but a lot of him, and kind of annoying.

VAN SUSTEREN: Rod, thank you.

BECKSTROM: Thank you, Greta.

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