2024 cyberattack on Kadokawa and Niconico

On the morning of June 8, 2024, Kadokawa's website and the Japanese video-sharing platform Niconico suffered a ransomware cyberattack by a Russian-linked hacker group called BlackSuit, who claimed responsibility for the attack.

[8][9] On June 9, Kadokawa reported the incident to the police, expert specialists, and the Kanto Local Finance Bureau.

On June 14, upon investigation, Kadokawa confirmed that the outage was caused by a ransomware cyberattack, and it was also found that despite remotely shutting down the website's services, the attackers were observed restarting the servers to continue to spread the malware; in response, Kadokawa physically disconnected the server's power and communication cable.

[1][11][12] On July 10, Kadokawa released a statement warning the public that disseminating any leaked information from the data breach would result in legal action.

[16] Kadokawa's publishing business' manufacturing end was briefly put on hold after the attack and e-books distribution was delayed.