Nikkei: unauthorized access to its Slack
Credentials exposed by malware on an employee's personal PC were believed to enable Slack access. The company identified the incident in September and changed passwords. Its November 4 notice identified possible exposure of names, email addresses and chat histories for 17,368 people. Leakage of reporting sources or reporting-related information was not confirmed.
Disclosed
2025-11-04
Organizations involved
1
Leaked or at risk
17.4K
17,368
Downtime
Unknown
Timeline
- Disclosed 2025-11-04
- 1 days
Attack or cause
- Method
- [Malware][Credential abuse]
- Impact
- [Data leak]
- Entry point
- Stolen credentials
Data exposed or at risk
Organizations involved
[Breached][Major]Tokyo, ChiyodaInformation and communications17,368 leaked
Nikkei Inc.
Sources
- [1][Official]業務用チャット・スラックへの不正ログインと情報流出についてNikkei Inc. · 2025-11-04