Disclosure context

About Avoslocker

**Overview**: AvosLocker is a financially motivated ransomware group that emerged in June 2021, operating as both a Ransomware-as-a-Service (RaaS) platform and conducting direct attacks against organizations worldwide. The group has demonstrated sophisticated capabilities and has targeted over 70 victims across multiple critical sectors. **Origin & Affiliation**: While the exact country of origin remains unclear, AvosLocker operates as a RaaS model, recruiting affiliates to conduct attacks using their ransomware payload and infrastructure. The group has shown no clear ties to state-sponsored activities, appearing to be purely profit-driven cybercriminals. **Attack Methodology**: AvosLocker typically gains initial access through compromised Remote Desktop Protocol (RDP) credentials, VPN vulnerabilities, and phishing campaigns, subsequently deploying tools like Cobalt Strike for lateral movement and persistence. The group employs double extortion tactics, stealing sensitive data before encrypting systems and threatening to publish the information on their leak site if ransom demands are not met. Their ransomware uses strong encryption algorithms and includes capabilities to terminate security processes and delete shadow copies to prevent recovery. **Notable Campaigns**: The group has particularly targeted critical infrastructure sectors including education, manufacturing, finance, healthcare, and transportation, with significant attacks reported against organizations in the United States, Germany, Singapore, Canada, and France. CISA and FBI have issued joint advisories warning about AvosLocker's targeting of critical infrastructure, highlighting the group's impact on essential services. **Current Status**: As of recent threat intelligence reporting, AvosLocker remains active, continuing to recruit affiliates and conduct ransomware operations against organizations globally. The group has been linked to 70 public disclosures across our corpus. First observed on a leak site on June 13, 2021; most recent post February 11, 2023. The operation is currently inactive.

Also tracked as: Avos.

Timeline of this disclosure

December 26, 2022McKenzie Health System listed by Avoslockeron the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Healthcare sector, which has 1,779 disclosures indexed across all operators we track. Geographically, McKenzie Health System is reported in United States, a country with 7,392 ransomware disclosures in our corpus.

How we know this. Darkfield monitors public ransomware leak sites continuously, archiving every new disclosure and the data later released against the victim. Each entry on this page is sourced from the operator's own publication and cross-checked against complementary OSINT feeds (RansomLook, ransomware.live, RansomWatch). We do not collect or host stolen data — only the metadata, timestamps and screenshots needed to make the public disclosure searchable and accountable. Records here are corrected when the original post is edited, retracted, or merged with another disclosure.

Ransomware victim disclosure

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McKenzie Health System

Claimed by Avoslocker · listed 3 years ago

41m

Age

since listed · data leaked

Status timeline

Listed
Dec 26, 2022
Data leaked

At a glance

Group: Avoslocker
Status: Data leaked
Country: United States
Sector: Healthcare
Listed on leak site: Dec 26, 2022

About the victim

AI dossier — public-source company profile

McKenzie Health System (MHS) is a not-for-profit medical and surgical hospital located in Sandusky, Michigan, with nine clinics serving the surrounding region. It provides inpatient and outpatient medical and surgical care to a rural community. As a regional health system, it handles sensitive patient health and administrative data.

Industry: Non-profit Hospital & Ambulatory Healthcare
Address: Sandusky, Michigan, United States

Attack summary

Severity: critical — The victim is a healthcare provider (hospital and clinic network); data_published status confirms exfiltration occurred, strongly implying regulated patient data (HIPAA-covered PHI/PII) has been exposed at scale.

AvosLocker claims to have attacked McKenzie Health System and has published data (disclosed status: data_published), indicating exfiltration of company and likely patient-related data.

critical

Data the group says was taken

AI dossier — extracted from the leak post

Patient medical records
Personal identifiable information (PII)
Hospital administrative data
Financial records
Staff personnel data

What the group claims

McKenzie Health System (MHS) is a not-for-profit medical and surgical hospital in Sandusky, Mich., with nine clinics in the surrounding region.

Source

Indexed 3 years ago

This page surfaces a public ransomware disclosure indexed by Darkfield. Original posts come from the operator's own leak site; we cross-check against ransomware.live, RansomLook and RansomWatch where applicable. Share this URL freely.