SEOUL, South Korea-A cyber attack on Wednesday caused the computer network of South Korea's major banks and top TV stations to collapse at the same time, causing the national banking machine to collapse and triggering speculation about North Korea's participation.
The screen was blank at 2 p. m. (0500 GMT), the state-
South Korea's information security agency says some systems remain paralyzed more than seven hours later.
Police and South Korean officials were unable to immediately determine responsibility, and North Korean state media did not immediately comment on the closure.
But some experts suspect it was a cyber attack planned by Pyongyang.
In the United States, competitors threatened each other. S. -
Military exercises in South Korea and military exercises in the United StatesN.
Sanctions aimed at punishing North Korea for its nuclear test last month.
Internet paralysis comes days after North Korea blamed South Korea and the United States. S.
Last week launched a cyber attack to close the site for two days.
Rocky Pacific, Thailand-
Internet service providers confirmed a power outage in North Korea, but did not say what caused it.
South Korea's closure did not affect government agencies, potential targets such as power plants or transportation systems, and did not immediately report that bank customers' records were leaked. But the chaos froze part of the country's business.
Some customers are unable to use debit cards or credit cards that many people rely on other than cash.
At a Starbucks in downtown Seoul, customers are asked to pay for coffee in cash and line up outside a disabled bank machine.
Shinhan Bank, South Korea's main Bank, reported that,
The one-hour system, including online banking and ATMs, was shut down.
The company said that the network later resumed online and the banking business returned to normal.
No customer records or accounts were leaked, Shinhan said.
Nonghyup, another large bank, said its system eventually returned to online status.
Officials did not answer the phone and asked the customer for details of the security record.
Jeju Bank said some of its branches also reported Network closures.
The broadcasters at KBS and MBC said their computers broke down at 2 in the evening. m.
However, the TV broadcast was not affected by the closure.
According to the state, about seven hours after the shutdown started, the computer was still off
Korea Telecom Regulatory Authority Korea Communications Commission.
The YTN cable news channel also said the company's internal computer network had been paralyzed.
The video shows workers staring at a blank computer screen.
KBS staff said they watched helplessly as the files stored on their computers began to disappear.
Last year, North Korea threatened to attack several news companies, including KBC and MBC, as they reported criticism of the Korean Children's Festival. [pullquote]
Lim Jong said: "This must be a hacker attack.
Dean, Graduate School of Information Security, Korea University.
"Cannot be shut down at the same time because of a technical failure.
"The Korea Information Security Agency reported that skull images and hacking statements suddenly appeared on some closed computers, but later said, those who reported the skulls did not work for the five companies whose computers had suffered massive downtime.
KISA is also investigating skull images.
"If it turns out that this is a state --
The sponsored attack, which is pretty bald, is definitely an escalation of tensions between the two countries, "said James Barnett, former US Secretary of Public Security and Homeland Security. S.
Federal Communications Commission
One ominous issue is that attackers may also see other businesses in South Korea or elsewhere, and Barnett says he is in charge of the cyber security business at Venable law firm in Washington.
"This requires a wake-up call --
He said, "call.
"This can happen anywhere.
An official with the South Korean Communications Commission said investigators speculated that the malicious code was spread from a company server that sent automatic updates to security software and virus patches. LG Uplus Corp.
Lee Jung, spokesman for the company-provides network services to companies suffering from power outages, but does not see signs of cyber attackshwan said.
South Korea's Defense Ministry says the South Korean military has increased its readiness for cyber attacks but has seen no signs of cyber attacks.
No government computers were affected, officials said.
President Park Geun-hye
According to her spokeswoman Kim Haing, hye called for a swift effort to get the system back online.
South Korea is the world leader in broadband and mobile Internet access, and the closure has raised concerns about the overall vulnerability of South Korea.
Previous hacking attacks against private companies leaked personal data from millions of people.
Past malware attacks have also disabled access to government agency websites and destroyed files in personal computers.
Seoul believes that North Korea operates a cyber-warfare force against American hackers. S.
South Korea's government and military networks collect information and disrupt services.
Seoul has accused North Korean hackers of launching several cyber attacks in recent years.
Pyongyang either denies or ignores the allegations.
Hackers who use IP addresses in China have also been blamed.
McAfee Inc. , a computer security software manufacturer, in 2011
He said North Korea or its sympath could be responsible for cyber attacks on South Korean government and bank websites earlier that year.
The analysis also said North Korea appears to be linked to a large computer of 2009.
Destroy cyber-based attacks in the United StatesS.
Government Internet sites.
Pyongyang denied involvement.
"North Korea has almost certainly done similar attacks before," said Tim Junio, a cyber security researcher at Stanford University's Center for International Security and Cooperation.
"This is not a more important part of the reason probably because South Korea takes the first major incident seriously and has deployed a range of organizational and technological innovations to reduce response time during future North Korean attacks.
"South Korea has set up a National Cyber Security Center, a national monitoring department and a cyber command that imitates the United States. S. Cyber Command.
"The security monitoring centers of these companies get fed information from all over South Korea to help detect events quickly and drive technology solutions," he said . ".
"They have also established formal relationships with governments and departments within companies working on national security, including North Korean malware.
"As the North Korean government closes, the threat of rhetoric and attacks from Pyongyang against the United States is escalating. N. sanctions.
Washington also expanded sanctions against North Korea this month to weaken the government's ability to develop its nuclear program.
North Korea has threatened retaliation for sanctions and ongoing US military action. S. -
South Korea's military exercise was described by allies as an example, but Pyongyang said it was preparing for the invasion.
On Wednesday, North Korean leader Kim Jong Un inspected a military exercise during which a drone hit a target and the rocket shot down a simulated enemy cruise missile.
Kim Jong Il told officers that the North should "destroy the enemy with no mercy, so that when the battle began, no one could survive and sign the surrender document, according to North Korea's Central News Agency.
Last week, the North Korean peace and reunification Commission warned South Korea's "reptile media" that North Korea was preparing a "precision strike" against Seoul ".
North Korea also claimed a cyber attack by the United States. S.
And South Korea.
North Korea's official North Korean Central News Agency has accused the countries of expanding their aggressive stance against Pyongyang to cyberspace through "intensive and ongoing viral attacks.
South Korea has denied the charge and the United States has denied it. S.
The military declined to comment.
Lin said he believes Chinese hackers could be the culprit of a power outage in Pyongyang, but North Korea could be responsible for Wednesday's attack.
"Hacking media companies is often due to political hopes of causing chaos in society," he said . ".
"The political attack on South Korea comes from North Korea.
Kwon Seok said: "It will take at least 1 to 6 months to coordinate the large-scale shutdown of large corporate networks.
Chul, executive director of Seoul-
Network security company based in Cuvepia Inc.
Quan, who analyzed the PC of one of the three broadcasters shut down on Wednesday, said he had yet to see signs of malware release from North Korea.
"But hackers left signs in computer files, which means it could be the first of many attacks," he said . ".
Lim said it would take several months to track the cause of the outage.