North Korea has doubled its number of cyber war personnel and established overseas bases for hacking attacks, as part of efforts to thwart hacking attempts against the country's infrastructures.
The number of elite personnel working for the North Korea's cyber war unit have now reached 5,900, compared to 3,000 two years earlier.
South Korea''s Yonhap news agency cited an undisclosed military source as saying, "The communist country operates a hacking unit under its General Bureau of Reconnaissance, which is home to some 1,200 professional hackers."
Hackers from North Korea have reportedly instigated cyber attacks through overseas bases in countries including China. Hackers also targeted South Korean military institutions, commercial banks, government agencies, TV broadcasters and media websites with malware deployments and virus carrying emails, with investigations into past major cyber attacks confirming their origin from North Korea.
However, the North has rejected allegations of its involvement, while in turn accused Seoul of fabricated the events to fan cross-border tensions.
South Korea has beefed up its Internet security budget to prepare experts since it established a special cyber command in 2010, in the midst of rising concern over its vulnerability.
Last April, South Korea alleged the North of executing cyber attacks the previous March that affected thousand computers and compromising electronic banking sites and ATM networks.