> JapanHacked_
[Resolved][Severity: Moderate][Ransomware]

Resonac: ransomware attack

Ransomware detected on May 20 led to network isolation and disruption of some operations, production and shipping. The August 6 final report announced completion of investigation and response, full malware removal and normal operations. Investigation found no major harm such as data leakage within its scope.

Disclosed

2025-05-20

Organizations involved

1

Leaked or at risk

Unknown

Downtime

Unknown

Timeline

  1. Detected, Disclosed 2025-05-20
  2. Resolved 2025-08-06
  3. 78 days

Attack or cause

Method
[Ransomware]
Impact
[Service outage]
Entry point
Unknown

Data exposed or at risk

–

Organizations involved

Open in organization search

Sources

  1. [1][Official]弊社にて発生したセキュリティインシデントについて(第一報)Resonac Holdings Corporation · 2025-05-20
  2. [2][Official]弊社にて発生したセキュリティインシデントについて(第四報)Resonac Holdings Corporation · 2025-06-03
  3. [3][Official]弊社にて発生したセキュリティインシデントについて(最終報)Resonac Holdings Corporation · 2025-08-06