Transcript for 'No company which can't be hacked': The remote Romanian town dubbed 'Hackerville'
series of raids, coordinated operations to take down suspected criminal enterprises. What these investigators are looking for, not drugs, or money -- but perhaps the most valuable currency on Earth. Information. It is the cornerstone of our connected world. And stealing it through hacking has become the crime of our time. There's many headlines, seems like every other week, there's a new data breach, more data has been lost or accessed. Reporter: Cyber crime cost the U.S. Economy anywhere between $50 billion and $100 billion in 2016. Digital cat burglars climbing into your computer screen instead of your window. We are in the middle of cyber war. Information is power. When you hold information, you have the power. Reporter: Tonight we're taking you on a journey to the other side of the headlines, onto the home turf -- Translator: Nobody can stop us, it's just not possible. Think of climbing Everest. I wanted to see how far I could go. Reporter: And into the mind of a hacker. When I want to hack something, I want to know what's the worst thing I can do? A snowy winter's day in Bucharest, Romania. We've come here because this country has a surprising claim to fame. It's one of the centers of hacking around the world. Russia, North Korea, and Romania. And we wanted to find out why. Romania may not be as notorious as well-known counterparts but over the last 20 years it's been a haven for some of the best hackers in the world. FBI special agent Peter trayvan has spearheaded the fight against cyber crime here. Romanian hackers are good? Very good, very professional criminals. Reporter: After the Romanian revolution and the fall of communism in 1989, the country endured a prolonged period of economic turmoil. After the end of communism, you have a lot of technically trained individuals. With the job market being what it was at the time, they realized that there was more of an effort could be made in making more money and turning to hacking. Reporter: Over the years it's created an underground industry, with Romanian hackers becoming known around the world. A man suspected of hacking into the e-mail of former president George W. Bush is under arrest in Romania. A man who goes by the nickname guccifer -- The individuals can make more money in the cyber underground compared to using those skill sets to work for private sector, the government. It makes it very hard to compete with the money that these individuals can make. Reporter: Hacking, as we hear it in the headlines, can mean a number of things. From gaining access to the information stored in a computer system to stealing passwords and breaching accounts, including e-mails and banking information. This is cert where the magic happens. Pretty much this is where the magic happens when it comes to incident response. Reporter: The national cybersecurity and incident response team in Romania, like the first responders for hacking attacks. How many incidents per year do you have to deal with? In 2017, we processed around 140 million alerts. 140 million alerts? Yeah. These alerts are computers telling other computers, I'm under attack? Yeah. Reporter: Attacks that come from hackers like Alex kotunia. Are you a hacker? Yeah, I am a hacker. I'm a good hacker. Most people in America hear hacker, they think you're a criminal, a vandal, a bad guy. I like to help. I want to make our I.T. Industry better. Reporter: Experts like Alex are called white hat hackers, good guys, security consultants hired by companies to hack them. Today he's going to attempt to hack Google, bit don't worry, he's allowed to do this. How much does Google pay up? Up to $40,000. $40,000 to hack Google, like a bounty hunter? Yeah. Have you made pretty good money doing this? I can pay my rent. I can have a better life. We're just sitting here at a restaurant in Bucharest using their wi-fi and you're starting to probe Google? Yeah. You can do it anywhere? Sometimes I do this from home, sometimes I go in a bar, having a cup of coffee, a tea. Sometimes I go to Starbucks. Yeah. Reporter: And despite the lure of the dark side, Alex continues to use his hacking exploits for good. You were never tempted? No, no. Because I know who I am. I cannot see my life like that. Hiding from police, from others. Reporter: But while people like Alex are the superheroes of the cyber world, we wanted to meet the other guys. Black hat hackers. The bad guys on the other side of the law. We've been driving for a couple of hours now through mountains, very traditional villages. We are about to head to a place very different. 45. No worries, man, no worries. This is a town that had many different organized groups of hackers -- Reporter: This city became a hotbed for cyber crime in the 1990s, and despite crackdowns by law enforcement, it gained a reputation as ground zero for hackers. It's here that we met this man. Translator: So there's companies and they have competition. Everyone is trying to get information on the others. So I'm a mercenary who gets paid to get that information from the competitors. The demand for information is huge. Reporter: His name? Well, he didn't want to share that. He says he is a hacker, a black hat, operating in the darkest corners of the internet. Just meeting him here in this nondescript location took months to set up. Translator: All of us wanted to prove who's the best. It's just fun. Even today it's a lot of fun for me. Reporter: He says he is from hackerville, having grown up here. And he claims to have hacked governments and companies for their information and has allegedly been paid big money for his efforts. Translator: We're talking about sums as high as tens of thousands of dollars or euros. If you have information on your competitors you'll always be one step ahead. I had clients who sometimes didn't just want information but wanted their competitors' databases damaged or destroyed or taken offline. Of course, this pays more. Reporter: ABC news could not independently verify his so-called hacking, ploits, some of which sound pretty lofty. Translator: Until today there hasn't been a company I couldn't hack. It may have taken longer or shorter but the accompanyingest thing is when people don't know we're there. You go in, pass on the information, and stay there like an invisible tick. Reporter: Black hat hackers and white hat hackers like Alex are on opposing sides of the so-called cyber war. One side fighting to break into systems and steal information. The other trying to stop them. So they really want that information? Yeah, because it's valuable. How do you stop a talented hackers? If you're a company? How would you stop you? The simplest way is to hire them. They will know the mindset of a hacker and they'll help your company. Reporter: Which is why some companies are doing just that. Cyber smart defense is a leading cybersecurity firm, you know, the good guys. But they hire some of the most notorious reformed former bad guys in their ranks. The bad guys, they will move from the street where they -- for example, they used to rob banks. These things are not happening anymore because it's much easier to hack a bank and then convert the money into Bitcoin or whatever cryptocurrency and make it disappear. Reporter: And in this war, they have soldiers. This is razvan, hacker nickname tinkode. Victor, hacker nickname sir Vick. In their past they both have been charged and jailed for hacking companies and government entities in the best. Victor, you must have known it was a crime? Yeah, I knew. I just didn't take it serious. I said, well, okay, even if they catch me and the police come, I'll probably get a slap on the wrist and move on. Instead you got a federal indictment in the United States? Yeah, yeah. Reporter: In our connected world that seems to be constantly under siege, companies like csd hope to beat the bad guys at their own game. You got an all-star team here. Yeah. They do now exactly what they used to do before. But now, of course, it's legal, authorized. Reporter: The company's founder, modalin, grew up in hackerville and is hoping to use his hometown's reputation to usher in the next generation of computer security experts. When it comes to I.T., Romania and hackerville will become the silicon valley of Europe. Reporter: And while international law enforcement, the Romanian national police and the FBI, have cracked down on cyber crime over the last decade -- I don't think it's the wild, wild west of the late '90s and early 2000s. Reporter: Just like technology itself, the threats continue to evolve. I think there is no company which can be hacked -- Which can't be hacked? Yeah. Reporter: In the long war against cyber crime, the good guys can never let up because the bad guys are always on the attack. Translator: Some buy anti-virus software and think they're safe. That has nothing to do with it. For me it's five minutes' extra work to hack them. As far as I'm concerned, sooner or later, anything can be hacked. Reporter: For "Nightline," I'm Terry Moran in Romania. Next, the young man who
This transcript has been automatically generated and may not be 100% accurate.