( CNN ) As the United States gets ready to blame the Sony hack on North Korea , a troublesome question is emerging : Just what is North Korea capable of ? Experts say the nation has spent scarce resources on building up a unit called `` Bureau 121 '' to carry out cyberattacks . North Korea has been blamed in the past for attacks in South Korea , but the Sony hack -- if indeed North Korea is behind it -- would seem to represent an escalation of tactics . `` I think we underestimated North Korea 's cybercapabilities , '' said Victor Cha , director of Asian Studies at Georgetown University . `` They certainly did n't evidence this sort of capability in the previous attacks . '' Cha was referring to attacks on South Korean broadcasters and banks last year . In March 2013 , South Korean police said they were investigating a widespread computer outage that struck systems at leading television broadcasters and banks , prompting the military to step up its cyberalert level . The South Korean communications regulator reportedly linked the computer failures to hacking that used malicious code , or malware . An investigation found that many of the malignant codes employed in the attacks were similar to ones used by the North previously , said Lee Seung-won , an official at the South Korean Ministry of Science . North Korea denied responsibility . A spokesman for the General Staff of the Korean People 's Army labeled the allegations `` groundless '' and `` a deliberate provocation to push the situation on the Korean Peninsula to an extreme phase , '' according to KCNA , the North Korean state news agency . North Korea has similarly denied the massive hack of Sony Pictures , which has been forced to cancel next week 's planned release of `` The Interview , '' a comedy about an assassination attempt on North Korean leader Kim Jong Un . But KCNA applauded the attack . `` The hacking into the SONY Pictures might be a righteous deed of the supporters and sympathizers with the DPRK , '' it said , using the acronym of its official name , the Democratic People 's Republic of Korea . `` The hacking is so fatal that all the systems of the company have been paralyzed , causing the overall suspension of the work and supposedly a huge ensuing loss . '' Experts point to several signs of North Korean involvement . They say there are similarities between the malware used in the Sony hack and previous attacks against South Korea . Both were written in Korean , an unusual language in the world of cybercrime . `` Unfortunately , it 's a big win for North Korea . They were able to get Sony to shut down the picture . They got the U.S. government to admit that North Korea was the source of this and there 's no action plan really , at least publicly no action plan , in response to it , '' said Cha . `` I think from their perspective , in Pyongyang , they 're probably popping the champagne corks . '' CNN 's Gregory Wallace , Brian Stelter , Evan Perez , K.J . Kwon and Jethro Mullen contributed to this report .
The United States is set to blame North Korea for the massive hack at Sony . It 's not the first time North Korea would be accused of launching such an attack . `` In Pyongyang , they 're probably popping the champagne corks , '' says one analyst .