Hackers who stole data from Japanese publisher Kadokawa in a cyberattack claim they have leaked even more stolen information, the company said Tuesday.
Kadokawa said it is investigating the authenticity of the claim and urged people not to share such information on social media as it could have serious consequences.
A hacker group calling itself BlackSuit published a statement on the dark web, a highly anonymous part of the internet, claiming responsibility for the data breach, which led to suspensions of Kadokawa services, including the video platform Niconico. They threatened to publish the data on Monday unless a ransom was paid.
The group is believed to have stolen 1.5 terabytes of data, including information about contracts with business partners and user information.
The Niconico platform and other services have been unavailable since June 8 following a cyberattack involving a ransomware virus that encrypts data and demands payment in exchange for a decryption key.
Kadokawa, which uses a temporary system, said on Friday that it had confirmed the leak of some of the data, including personal information of all employees at its Dwango unit, which manages the Niconico platform.
