SEOUL - Two banks and three major broadcasting stations in South Korea went into shutdown mode on Wednesday in what is a suspected hacking from North Korea.

According to Korean news agency Yonhap, three broadcasters, three banks and two insurance firms reported to the National Police Agency that their computer networks were entirely halted at around 2 p.m. local time for unknown reasons. Woori Bank, a leading lender in Seoul, also came under an apparent hacking attack at the same time but managed to defend its computer networks through an internal system.

The state-run Korea Information Security Agency (KISA) said that skulls popped up on the screens of some computers – a strong indication that hackers planted a malicious code into the South Korean systems. It was only two and a half hours later that some computers were able to get back online. 

The AP reports that Shinhan Bank’s online banking and ATMs suffered from the attack. The company could not conduct any customer activities at bank windows, nor retail and corporate banking. 

Seoul is a largely cashless city and it was reported that a Starbucks in the center could only take cash payments so queues formed outside the coffee shops, as well as at the defunct ATMs nearby.

A South Korean ATM. Photo by Excretion

An expert professor in the information Protection Department of Korea University, Lim Jong-in is quoted in the Korea Times as saying that “The hacking was not initiated at an individual level. An individual could hack into the network of one institution, but cannot conduct simultaneous attacks as happened.” When asked about the possibility of a North Korean attack, he replied, “Cyber terror is one of the easiest ways for them to attack the South as it does not damage humans.”

Tensions have been running high on the Korean peninsula during the past few weeks after the UN Security Council's ruling on North Korea’s nuclear weapon tests. Yonhap reports that the South has accused the North of carrying out cyber attacks over the past few years, although the North denies these allegations. 

The government enhanced their "infocon" level- an alert for cyber terror says the Korea Times. "We do not rule out the possibility of North Korea being involved, but it's premature to say so," Defense Ministry spokesman Kim Min-seok said.