Career Design Center: a credential-stuffing attack on the "Onna no Tenshoku type" job site led to 38,442 unauthorized logins by 18,253 users

A credential-stuffing attack on the job site "Onna no Tenshoku type" logged into 38,442 accounts (18,253 users); member pages may have been viewed.

Disclosed

2026-05-30

Organizations involved

Leaked or at risk

18.3K

18,253

Downtime

Unknown

What happened

2026-05-26
A credential-stuffing attack, apparently using credentials obtained elsewhere, began. It continued until May 28. [1] [2]
2026-05-30
It announced the unauthorized logins. There were 1,141,828 attempts, of which 38,442 logins (18,253 users) succeeded, and some member information pages may have been viewed. [1] [2]
2026-06-19
It published its investigation results. The forensic investigation and the internal investigation did not differ. [3]

[Breached][Major]Tokyo, MinatoOther services18,253 leaked
Career Design Center Co., Ltd.
Member accounts were logged into through a credential-stuffing attack and member pages may have been viewed.

						Note
Career Design Center Co., Ltd.	[Breached]	[Major]	Tokyo, Minato	Other services	18,253	Member accounts were logged into through a credential-stuffing attack and member pages may have been viewed.