A cybercriminal group operating under the name Chaos has posted a claim on its dark web leak site alleging that it targeted Mankato Clinic, with the listing dated September 10, 2026. This claim was tracked by ransomware.live, a security research platform that monitors the public leak sites operated by ransomware groups. At this stage, the claim comes solely from the group itself, and there has been no independent confirmation from Mankato Clinic, from a regulator, or from any third-party cybersecurity authority. As with any extortion-site posting, the assertion should be treated as unverified until the organization or an official body says otherwise.
What the leak-site posting says versus what remains unconfirmed
- Claimed date of posting: September 10, 2026
- Group behind the claim: Chaos
- Alleged target: Mankato Clinic, operating in the healthcare field
- The specific categories of data the group claims to have obtained — such as patient records, financial details, or employee information — have not been disclosed publicly or verified by any independent source
- No statement from Mankato Clinic confirming or denying the incident has been located at the time of this writing
Precautions worth taking while this claim remains unresolved
- Change passwords associated with any accounts tied to Mankato Clinic or related patient portals, choosing unique credentials rather than reused ones
- Turn on two-factor authentication wherever it is offered, particularly for email, banking, and healthcare portal logins
- Stay alert for phishing attempts, including emails or calls posing as clinic staff, insurers, or billing departments that ask for personal or payment information
- Review financial and medical billing statements regularly for any activity you don’t recognize
- Consider a service like a service like Aura or LifeLock for ongoing identity monitoring, which can help flag suspicious use of your personal information sooner rather than later
BreachLetter will revisit and update this article if Mankato Clinic issues a statement, confirms an incident, or if the matter is reported to regulators or made public through official channels.