Cyber Threat Intelligence
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Ransomware Victim Public Sector

Winona County

Ransomware attack by Interlock · Disclosed May 1, 2026 · 🇺🇸 United States

winonacounty.gov

Date Disclosed
May 1, 2026
2026
Threat Group
Interlock
125 total victims
Country
🇺🇸 United States
Industry
Public Sector

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

Winona County 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 1, 2026, when Winona County appeared on the group's dark web leak site.

Winona County is based in United States , operating in the Public Sector sector. United States ranks #1 globally for ransomware attacks, with 9,415 victims in our database.

Sector context: Organisations in this sector hold valuable data and operational systems that ransomware groups seek to exploit for financial gain through encryption and data exfiltration.

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 16:00 UTC.

Frequently Asked Questions

Was Winona County attacked by ransomware?

Yes. Winona County was listed as a victim of the Interlock ransomware group on May 1, 2026. The organisation is based in United States and operates in the Public Sector sector. The disclosure appeared on the group's dark web leak site.

Which ransomware group attacked Winona County?

Winona County 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 Winona County ransomware attack occur?

The ransomware attack on Winona County was disclosed on May 1, 2026. 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 Winona County ransomware attack?

The specific data stolen from Winona County 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 Public Sector organisation, Winona County likely held sensitive business data, client information, and operational 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.