On New Year’s Eve, a hacker group known as The Dark Overlord announced it had breached a US law firm and found a trove of undisclosed information regarding the 9/11 attacks and leaked some of the files online.

Two months after The Dark Overlord released the first batch of hacked information, allegedly related to the terrorist attacks on 11 September 2001, someone has disclosed the decryption key for the third layer of the material, Motherboard reported. The stolen data reportedly contains thousands of emails, some of which were sent between different law firms.

READ MORE: Cash for Cache: Hackers Reveal First Batch of 9/11 Files in Blow to 'Deep State'

While the group was banned from Twitter, Reddit, Steemit and Pastebin, Motherboard reported that someone left a message at a “popular paste website”, but failed to provide a link to the source.

“You want the True [sic] about 9/11. Here is you change”, the message along with a link to the emails read, according to Motherboard.

Motherboard claims it has verified that the key works, and reported that the folder includes some 5GB of material, including 8,000 emails.

In its New Year’s message, The Dark Overlord claimed it had hacked different law firms and insurers, including Hiscox Syndicates Ltd, Lloyds of London, and Silverstein Properties.

Back in January, a spokesperson for the Hiscox Group told Motherboard that the cyber crooks had compromised a legal firm that consulted the company:

“The law firm’s systems are not connected to Hiscox’s IT infrastructure and Hiscox’s own systems were unaffected by this incident. One of the cases the law firm handled for Hiscox and other insurers related to litigation arising from the events of 9/11, and we believe that information relating to this was stolen during that breach. Once Hiscox was informed of the law firm’s data breach, it took action and informed policyholders as required. We will continue to work with law enforcement in both the UK and US on this matter”.

The Dark Overlord released decryption keys for two batches of what it claimed was an archive of 9/11 litigation documents in January after demanding a ransom, denominated in Bitcoins.

READ MORE: New 9/11 Files: Lawyers Discussed Whether Bush Knew About Attacks in Advance

The encryption keys were shared via Twitter, but the platform was quick to ban the group’s account. The Dark Overlord was subsequently removed from Reddit, Steemit, and Pastebin.

When exploring the stolen cache, they allegedly found “hundreds of gigabytes of litigation-related documents”, including a total of 18,000 emails, non-disclosure agreements, expert witness testimonies, and communications with government officials.

The cyber extortionists split the papers into five layers, with Layer 1 being marked as the most insignificant material, while Layer 5 standing for the most sensitive data.

They have also called on concerned government agencies, firms and individuals to come and get the papers as they will ultimately be “buried” with the revelations. The cyber thieves teased that the data dump would outshine “both in volume and impact” Edward Snowden’s leak of docs on mass surveillance in the US.

READ MORE: Deep State Doesn't Seem Bothered by 9/11 File Hackers' Threats – Ex-USAF Colonel

On 11 September 2001, al-Qaeda terrorists hijacked airplanes to bring down the twin towers of New York City’s World Trade Centre and attack the Pentagon. The worst attack in the history of the United States claimed the lives of some 3,000 people. The 9/11 attacks have been shrouded in mystery, with many people laying out various conspiracy theories in a bid to explain how the catastrophe happened.