[Investigating][Severity: Critical][Intrusion]

Tsukaeru.net: customer data leaked from Tsukaeru Portal; shared servers also breached

Tsukaeru Portal customer data leaked and encrypted passwords may have been cracked. Shared servers were restored to 2 November, losing later site updates and mail.

Disclosed

2026-11-07

Organizations involved

Leaked or at risk

Unknown

Downtime

Unknown

What happened

2026-11-06
Tsukaeru.net noticed abnormal behaviour on a server it manages and began investigating, which revealed unauthorized access and a leak of customer data. [1]
2026-11-07
It published a first report. How and when the attacker got in is still being investigated. [1] [2]

Impact

Customer data in Tsukaeru Portal, used for contracts and purchases, leaked. Which fields were viewed or taken is under investigation. Stored passwords were encrypted but may have been decrypted. Card data is not kept in the portal and did not leak. [1]

Unauthorized access was also found on some shared servers, which were restored from 2 November backups. Website changes and mail sent or received between that backup and early 7 November were lost. The 127 VPS on an affected host are being checked; that is not a count of confirmed intrusions. [1]

Response

It stopped or restricted the affected systems, updated software and reviewed credentials. The portal was restored from a backup taken before the intrusion and all login passwords were reset. Users must set a new password and redo two-factor authentication, and should change the same password wherever else they use it, especially for email. [1]