According to Security NEXT, Mynavi subsidiary 444 announced that a development server for its TechFUL service was breached in December 2024, potentially exposing personal information of contractors and users [1]. The company confirmed the intrusion after receiving an alert from its cloud management provider and discovered on December 13 that a database had been destroyed alongside a ransom demand threatening to publish confidential data [1]. Up to 45,576 accounts registered on or before August 13, 2023, may be affected, including names, addresses, hashed passwords, and educational and work history [1].
This event has not been officially confirmed. Content is based on media or third-party reports.
Backfill: this event became public on Dec 27, 2024 and we added it on Nov 10, 2026. It is not a new event.
HighMonitoringBackfillMedia reported
444's TechFUL Development Server Breached, Database Destroyed, and Ransom Note Left Behind
1 min read
- Disclosed
- Dec 27, 2024
- Published
- Nov 10, 2026
- Last updated
- Nov 7, 2026
- CVSS basis
- Our assessment
- Attack vector
- Actor type
- Motivation
On this page
30-second summary
What happened
Who is affected
Industries mainly affected: Technology
What to do nowOur advice
Up to 45,576 accounts registered on or before August 13, 2023, may be affected, including names, addresses, hashed passwords, and educational and work history [1].
Timeline
- Security NEXT publishes report (date only; timestamp is a placeholder)[1]
Technical details
Verified Source Summary
Mynavi subsidiary 444 announced that a development server for its TechFUL service was breached in December 2024, potentially exposing personal information of contractors and users [1].
The company confirmed the intrusion after receiving an alert from its cloud management provider and discovered on December 13 that a database had been destroyed alongside a ransom demand threatening to publish confidential data [1].
Up to 45,576 accounts registered on or before August 13, 2023, may be affected, including names, addresses, hashed passwords, and educational and work history [1].
References
Media1
- [1]
“マイナビの子会社で、学校向けのプログラミングスキル測定サービス「TechFUL」を展開する444は、同サービスの開発用サーバが侵害され、契約者やユーザーに関する個人情報が外部に流出したおそれがあることを明らかにした。”
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