CSIDB logo
Incident

Niconico

Incident posture

Attack window
Jun 2024
Location
Japan
Status
Historical
CIA posture
Available to members
Updated
2025-12-30 16:06

Linked entities

Victim
Niconico
Threat actors
0 actors
Sources
2 sources

Timeline

Occurred
Jun 2024
Discovered
Pending
Disclosed
Pending
Resolved
Pending

Summary

The video-sharing platform Nico Nico Douga suspended all services following a large-scale cyberattack targeting its infrastructure. Operator Dwango implemented emergency countermeasures while investigating the incident's scope, confirming related unauthorized access attempts against parent company Kadokawa's corporate website and e-commerce portal. The publisher initiated forensic analysis to determine potential data compromise, collaborating with external cybersecurity specialists and law enforcement. Service restoration remains delayed pending comprehensive security validation and mitigation of attack impacts across affected systems.

Motives

Detailed motive labels are available to members.

4 motives

TTPs

Detailed technique labels are available to members.

1 technique

Description

On June 1, 2024, Dwango, operator of the Japanese video-sharing platform Niconico, suspended services following a large-scale cyberattack. The company announced the suspension late Saturday, stating the action aimed to minimize the attack's impact. Dwango initiated a thorough investigation and implemented countermeasures but cautioned that service restoration would not occur until safety could be assured and attack effects mitigated. The operator explicitly stated that services would remain offline throughout the weekend. Parent company Kadokawa confirmed related disruptions affecting its official website and e-commerce platform Ebten, citing potential unauthorized external access. Kadokawa's disclosure noted the issues began affecting multiple group websites in the early hours of Saturday morning.

The cyberattack caused significant operational disruptions across Niconico and Kadokawa Group's digital properties. Kadokawa issued a public apology for the inconvenience and concern generated by the incident. Their investigation focused on determining the attack's full impact, including whether information leaks had occurred. The company engaged external cybersecurity experts and coordinated with law enforcement authorities during the response. Dwango committed to providing a further update on Monday, June 3, regarding restoration progress. No specific timeline for full service recovery was provided at the time of initial announcements. The incident marked one of the most severe service interruptions in Niconico's recent operational history, affecting both content delivery and corporate infrastructure.

Sources

Sources available to members: 2 sources.

CSIDB