Disclosure context

About cephalus

Based on available public information, Cephalus is a recently emerged ransomware group first observed in August 2025, operating with apparent financial motivations targeting organizations primarily across the United States, United Kingdom, Netherlands, and Ireland. The group has claimed 19 victims since emergence, with no publicly documented country of origin or confirmed affiliations to established ransomware families or RaaS operations by major security researchers or government agencies. Their attack methodology and specific technical capabilities remain largely undocumented in public threat intelligence reporting, though their targeting pattern shows focus on healthcare, business services, financial services, and manufacturing sectors alongside organizations of undetermined industry classification. No major high-profile campaigns, record ransom demands, or law enforcement disruption actions have been publicly reported by CISA, FBI, or established security research firms at this time. The group appears to remain active as of current reporting, though the limited public documentation suggests either highly targeted operations or insufficient analysis coverage by major threat intelligence organizations. The group has been linked to 19 public disclosures across our corpus. First observed on a leak site on August 26, 2025; most recent post August 29, 2025. The operation is currently inactive.

Timeline of this disclosure

August 26, 2025CareSTL Health listed by cephaluson 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, CareSTL Health 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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CareSTL Health

Claimed by cephalus · listed 9 months ago

Age

since listed · data leaked

Status timeline

Listed
Aug 26, 2025
Data leaked

At a glance

Group: cephalus
Status: Data leaked
Country: United States
Sector: Healthcare
Listed on leak site: Aug 26, 2025

About the victim

AI dossier — public-source company profile

CareSTL Health is a federally qualified health center (FQHC) that has served the North St. Louis community for more than 50 years. It provides comprehensive, integrated healthcare services across the full spectrum of life—including family practice, pediatrics, behavioral health, dental, women's health, prenatal care, pharmacy, and more—operating multiple clinic locations. The center serves vulnerable and underserved populations on a sliding-fee schedule and accepts Medicaid.

Industry: Federally Qualified Health Center (Community Healthcare)
Address: North St. Louis, Missouri, United States

Attack summary

Severity: critical — 500+ GB of data exfiltrated and published from a federally qualified health center serving vulnerable populations; data almost certainly includes regulated PHI/PII at scale (medical, behavioral health, prenatal, pediatric), constituting a HIPAA-covered breach. The CEO statement also confirms a 30-day operational disruption, indicating both exfiltration and significant operational impact.

The ransomware group 'cephalus' (operating under the KAWA4096 moniker) claims to have exfiltrated over 500 GB of data from CareSTL Health and has published the data. The CEO's site statement references a 30-day operational disruption consistent with a ransomware-related incident, corroborating the attack claim.

critical

Data the group says was taken

AI dossier — extracted from the leak post

Patient medical records
Behavioral health records
Prenatal and women's health data
Pediatric health records
Insurance and billing information
Employee/HR records
Financial and reimbursement data
Medicaid enrollment data
Pharmacy records

What the group claims

CareSTL Health DATA Leak | 500+GB | KAWA4096 STEALED our data

Sources

Victim sitecarestlhealth.org
Leak posthttps://darkforums.st/Thread-CareSTL-Health-DATA-Leak-500-GB

Source

Indexed 9 months 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.