Sony Pictures suffered a massive hack last week, as peviously reported, in fact it is pretty much the worst hack in corporate history.

The story initially hit the headlines when it became known that a number of unreleased films had been stolen from the company's servers and uploaded to popular torrent-sharing websites - but it has since become clear that this was only the tip of the iceberg.

Things took a sinister twist when news leaked that North Korea is being treated as a suspect - and that up to 100 terabytes of sensitive data has been stolen and is being fed to media outlets.

North Korea update

The initially far-fetched speculation that North Korea was behind the attack was given a firm footing when a Federal Bureau of Investigation (FBI) report was leaked, saying that some of the malicious software used to hack into Sony's system was in Korean. Hackers used similar malware to launch attacks on businesses in South Korea and the Middle East, including one against oil producer Saudi Aramco that shut down some 30,000 computers.

A confidential five-page report was sent by the FBI to security specialists in American corporations. News agency Reuters learned of the secret warning and provided technical details about the attack. It also advised on how to respond if other corporations suffer similar breaches. The FBI also instructed companies to contact the agency if they identify similar malware.

North Korea has been out-spoken in its criticism of Sony Pictures up-coming film, The Interview which is set for release on Christmas day in the US. The comedy's plot sees Seth Rogan and James Franco travel to North Korea and attempt to assassinate North Korean leader Kim Jong-Un. 

A spokesperson for the North Korean foreign ministry previously issued a threat to BBC News, promising a retaliation for the film, saying: "Making and releasing a movie on a plot to hurt our top level leadership is the most blatant act of terrorism and war and will absolutely not be tolerated."

When asked by Reuters if Pyongyang was behind the Sony attack, a spokesman for North Korea's UN mission said: "The hostile forces are relating everything to the North Korea. I kindly advise you to just wait and see".

The obvious headline from that comment was: "Wait and see" - which seems like a vaguely threatening non-denial. But in the context of the full statement, it can also be read as saying, 'Everything is being blamed on us but wait and see and you will realise that you are wrong'.

The Verge, a partner-site of Vox Media which covers a mix of culture and technology, even ran the headline, "How did North Korea take control of Sony Pictures' servers?"

Re/code - a tech site which has been posting a steady flow of information from "sources close to the investigation" inside of Sony - is also reporting that they have been told that the company are close to formally announcing that North Korea was behind the attack.

In contrast to this, a North Korean diplomat in New York has offered the first formal denial that North Korea carried out the attack. He said: "Linking [North Korea] to the Sony hacking is another fabrication targeting the country," adding, "My country publicly declared that it would follow international norms banning hacking and piracy."

The Pyongyang representative spoke to US broadcaster Voice of America but asked to remain anonymous.

While poor diplomatic ties between North Korea and the rest of the world along with the secretive nature of the FBI and Sony investigations are creating confusion, it is still premature to say that North Korea was involved in the attack.

Other suspects

Wired reports that the hackers' moniker - Guardians of Peace (the name of the group who claimed responsibility for the attack) - as well as the imagery that they use, the tone of their communications, and some of the technical details of the attack, point to traditional hacktivists - rather than a national agency.

The attack could have been carried out by any number of anarchic anti-corporate groups - or possibly, as Wired suggests - a group of disgruntled Sony insiders.

Playing the media

The actual hackers have been actively communicating with journalists - and feeding them stolen documents. Buzzfeed was one of the media outlets who the hackers contacted, giving them almost 40GB of stolen files. After an initial review of this data the site concluded that: "Sony Pictures appears to have suffered the most embarrassing and all-encompassing hack of internal corporate data ever made public."

They also report that the hackers' email included the ominous message: "We have much more interesting data ... If you find special interest, send an email."

What's out there already?

• The initial leak of unreleased and recently released films: Fury, Mr Turner, Annie, Still Alice, and To Write Love on Her Arms.
• A secret script for a TV pilot, written by Breaking Bad creator Vince Gilligan.
• Spreadsheets containing the salaries of 6,800 employees.
• The Social Security numbers for 3,500 U.S. staff.
• An internal memo sent to Sony staff was leaked to the Hollywood Reporter and says: "We are not yet sure of the full scope of information that the attackers have or might release, we unfortunately have to ask you to assume that information about you in the possession of the company might be in their possession."
• It is believed that email archives and over 700 confidential documents have been stolen.
• Significant documents about Sony Pictures' business practices and prospects have been leaked - detailed confidential data about the business is already appearing in the media.

Away from the initial dent caused by the leaked content - and the North Korean plot - this attack is set to have massive ramifications for both the company and its shareholders.