(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 cyber-attacks.
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 cyber capabilities," said Victor Cha,
director of Asian Studies at Georgetown University. "They certainly
didn'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 cyber-alert 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 cyber crime.
"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.
