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Published signals
currently linked to this company
Company intelligence
Mizuho cybersecurity incidents and threat signals
mizuho.com
This company page brings together public reporting currently associated with Mizuho. It reflects signals published by Shadow Tier and should not be read as a complete incident history.
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Last 28 days
recent published signals
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Last 90 days
recent published signals
0
High or critical
confidence classifications
June 26, 2026
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most recent published signal
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Based on all published signals currently linked to Mizuho. Affected countries come from victim data; the company country above remains a separate profile fact. Counts describe this reporting set, not overall incident prevalence.
Attack patterns
Company signals
All published signals involving Mizuho
Mizuho Employee Data Compromised in Chain IQ Breach
As a client of Chain IQ, Mizuho was impacted by the Chain IQ data breach, which was claimed by the Worldleaks ransomware group on June 11, 2025. The breach resulted in the compromise of employee business contact details, including internal phone numbers, of selected Mizuho employees.
FAQ
Questions about Mizuho cybersecurity reporting
What does the Mizuho page include?
It combines a reviewed organization profile with all current published Shadow Tier signals explicitly linked to Mizuho.
Does every mention of Mizuho appear here?
No. A signal must contain a reliable company connection and meet the publication criteria; incidental or ambiguous mentions are excluded.
Why can the incident count change?
The page follows current published reporting. Counts change as new evidence is added, classifications are reviewed, or older signals leave the reporting window.