South Korea says that North Korea's top spy agency was behind a series of cyber-attacks on banks and broadcasters last month.
Shinhan Bank and Nonghyup Bank both saw their systems go down briefly in March, knocking out ATMs, POS terminals and mobile banking services. TV networks YTN, MBC and KBS were hit at the same time, sending computers crashing.
Having completed an initial investigation, South Korea's Ministry of Science, ICT and Future Planning has pointed its finger at the Reconnaissance General Bureau, Pyongyang's intelligence agency, which is believed to be overseeing an elite unit of thousands of cyber warfare experts, says the Korea Herald.
The investigation found that more than 30 of the 76 different types of malicious code collected from equipment affected by the attack were identical to those used in previous hits from the North. In addition, 22 of the 49 internet protocol addresses involved were the same as those used in cyber-attacks carried out by North Korea since 2009.
The attackers are thought to have gained access to computers and servers at least eight months before striking, monitoring systems before sending out a command to delete data and distribute malware.
Although long in the planning, the attacks came as tensions on the Korean peninsula again bubbled to the surface. In a further escalation, this week the North told foreigners in the South to "work out measures for evacuation" to avoid becoming involved in a "thermonuclear war".