Cyber Incident Victim: Ministry of Justice
Date:
May 2023
Location:
Japan
Summary
The Ministry of Justice and affiliated agencies experienced intermittent website outages due to a cyber attack claimed by Anonymous, protesting Japan's refugee policies. The DDoS attack caused unstable access and temporary inaccessibility, resolved by the next morning, with no data breach reported; authorities are investigating the incident's origins.
| CIA Posture | Motives | Tactics, Techniques & Procedures |
|---|---|---|
| Available to members | 1 motive | 1 technique |
| Threat Actor | Type | Location |
|---|---|---|
| 1 actor | Available to members | Available to members |
Description
On May 8, 2023, at approximately 11:00 PM Japan Standard Time, the Japanese Ministry of Justice began experiencing intermittent accessibility issues across multiple official websites, including its primary homepage and affiliated sites operated by the Public Prosecutors Office, Immigration Services Agency, and Public Security Intelligence Agency. The disruptions manifested as either complete inability to access content or unstable connections that significantly hindered navigation. By early May 9, a hacker collective identifying as "Anonymous" claimed responsibility through social media, explicitly linking the cyberattack to protests against Japan's refugee policies. The group's statement coincided with ongoing technical investigations by ministry officials, who attributed the service degradation to abnormal traffic surges characteristic of distributed denial-of-service (DDoS) attacks—a method historically associated with Anonymous operations.
Justice Minister Ken Saito confirmed during a May 9 post-cabinet press conference that initial disruptions were temporarily resolved before recurring in the early morning hours. Restoration efforts partially succeeded by 8:20 AM JST, when the main ministry homepage regained functionality, though subsidiary sites reportedly continued experiencing instability. Technical teams prioritized identifying the attack's origin while implementing unspecified countermeasures. The ministry issued a public apology for service interruptions but did not disclose forensic details regarding traffic volumes, targeted infrastructure, or data compromise. Historical context indicates this incident aligns with Anonymous' established pattern of DDoS attacks against Japanese entities, including prior operations in 2013 against Wakayama prefecture over dolphin hunting protests, 2016 aquarium-related attacks, and January 2023 disruptions to Shibuya Ward's website opposing park redevelopment. The collective's decentralized structure—comprising numerous anonymous participants globally—complicates attribution of specific subgroups or individuals involved in this incident.