> JapanHacked_

Cyberattack and data leak statistics for Japan

Incidents disclosed in Japan, counted by prefecture, month of disclosure, and attack method or cause.

RangeRange–

Incidents by prefecture

Incidents tracked
323
Data leaked or at risk (total)115 incidents of unknown size
428.7M
Affected organizations listed
488
Ransomware
49
Hit through a supplier
61
Okinawa

Most incidents

  1. Tokyo 211
  2. Osaka 38
  3. Aichi 21
  4. Kanagawa 14
  5. Fukuoka 13
Incidents012–34–78–1516+By registered office and disclosure date; an incident spanning prefectures counts in each. Click to list them.

Incidents per month (disclosed) · 2025/11–2026/10

Incidents per month (disclosed)039781171562025/11: 77112025/12: 77122026/1: 111112026/2: 141422026/3: 121232026/4: 9942026/5: 151552026/6: 191962026/7: 101072026/8: 313182026/9: 343492026/10: 1541541020252026

Attack methods and causes

  • Intrusion136
  • Credential abuse58
  • Web app exploit53
  • Ransomware49
  • Misconfiguration19
  • Unknown12
  • Malware10
  • API abuse9
  • Phishing9
  • Lost device6
  • Insider5
  • Misdelivery2