Underground groups of North Korean hackers are operating in China , defector says . They 're based in Beijing , he says , near the North Korean embassy . `` It 's easy for them to work secretly . North Korean officials in Beijing and other government officials declined to comment .
Underground groups of North Korean hackers are operating in China , defector says . They 're based in Beijing , he says , near the North Korean embassy . North Korean officials in Beijing and other government officials declined to comment .