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Kalamazoo Public School District

Ransomware attack by Interlock · Disclosed May 23, 2025 · 🇺🇸 United States

kalamazoopublicschools.com

Date Disclosed
May 23, 2025
2025
Threat Group
Interlock
125 total victims
Country
🇺🇸 United States
Industry
Education

ThreatAI Analysis

Compiled from this incident record and the threat intelligence profile for Interlock. Figures and technique mappings are quoted from the source data, not inferred.

About the Interlock group

Interlock is a ransomware group first observed in September 2024 that targets critical infrastructure sectors including healthcare, government, education, and technology across North America and Europe using double-extortion, with 57+ claimed victims including a major US dialysis provider exposing over two million patient records. Interlock has listed 119 victims since December 2023.

Incident Analysis

Kalamazoo Public School District was targeted by Interlock ransomware, one of the most active ransomware groups in our database with 125 confirmed victims globally. The attack was disclosed on May 23, 2025, when Kalamazoo Public School District appeared on the group's dark web leak site.

Kalamazoo Public School District is based in United States , operating in the Education sector. United States ranks #1 globally for ransomware attacks, with 9,416 victims in our database.

Sector context: Educational institutions often have under-resourced IT security teams and hold large amounts of student and faculty personal data, making them attractive targets for ransomware groups.

Interlock typically employs a double extortion model: first exfiltrating sensitive data from the victim's systems, then deploying ransomware to encrypt files. Victims face two simultaneous threats — paying to restore access and paying to prevent publication of stolen data. The group's leak site publishes victim names and exfiltrated data as leverage.

Data source: This incident record is sourced from public ransomware group leak site disclosures aggregated via the ransomware.live API. Disclosure date reflects when the victim was published on the leak site, which may differ from the initial date of compromise. This platform does not publish or link to stolen data. Last data update: Sep 5, 2026 18:00 UTC.

Frequently Asked Questions

Was Kalamazoo Public School District attacked by ransomware?

Yes. Kalamazoo Public School District was listed as a victim of the Interlock ransomware group on May 23, 2025. The organisation is based in United States and operates in the Education sector. The disclosure appeared on the group's dark web leak site.

Which ransomware group attacked Kalamazoo Public School District?

Kalamazoo Public School District was attacked by Interlock ransomware. Interlock is one of the most active ransomware groups, having claimed 125 victims globally. The group typically employs a double-extortion model: encrypting the victim's files and threatening to publish stolen data.

When did the Kalamazoo Public School District ransomware attack occur?

The ransomware attack on Kalamazoo Public School District was disclosed on May 23, 2025. This date reflects when the victim was published on the threat group's leak site, which may differ from the actual date of initial compromise.

What data was stolen in the Kalamazoo Public School District ransomware attack?

The specific data stolen from Kalamazoo Public School District has not been independently verified by this platform. Ransomware groups typically exfiltrate data before encrypting systems and use the threat of publication to pressure victims. As a Education organisation, Kalamazoo Public School District likely held student and faculty personal data and academic records.

How can organisations protect against Interlock attacks?

To defend against Interlock and similar threat actors, organisations should: maintain regular offline backups tested for restoration; implement network segmentation to limit lateral movement; deploy multi-factor authentication on all remote access; use endpoint detection and response (EDR) tools; conduct regular phishing and security awareness training; and monitor threat intelligence feeds for indicators of compromise (IOCs) associated with active groups.