Disclosure context

About insomnia

Based on the limited publicly available information, Insomnia is a relatively new ransomware group that first emerged in February 2026, appearing to be financially motivated based on their targeting patterns and operational behavior. The group's country of origin and potential affiliations with other ransomware operations remain unknown, with insufficient public documentation from major threat intelligence sources to determine whether they operate as a Ransomware-as-a-Service model or as an independent entity. Their attack methodology and specific technical capabilities have not been extensively documented by CISA, FBI, or major security research firms, though their targeting of 29 known victims across healthcare, technology, manufacturing, and hospitality sectors in the United States, Singapore, and Brazil suggests a broad opportunistic approach rather than highly selective operations. Given the group's recent emergence and limited public reporting from established threat intelligence sources, there are no widely documented notable campaigns or high-profile incidents that have garnered significant attention from law enforcement or major security vendors. As of current reporting, the operational status of Insomnia remains unclear due to the lack of comprehensive public analysis from authoritative sources, making it difficult to assess whether the group remains active or has ceased operations. The group has been linked to 34 public disclosures across our corpus. First observed on a leak site on February 7, 2026; most recent post April 28, 2026. The operation is currently active.

Timeline of this disclosure

April 2, 2026*****d **d**** ****o** listed by insomniaon the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Not Found sector, which has 4,859 disclosures indexed across all operators we track. Geographically, *****d **d**** ****o** is reported in US, a country with 2,713 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

← All victims

United Medical Doctors

listed as *****d **d**** ****o** · Claimed by insomnia · listed 2 months ago

48d

Age

since listed · data leaked

Status timeline

Listed
Apr 2, 2026
Data leaked

At a glance

Group: insomnia
Status: Data leaked
Country: US
Sector: Not Found
Listed on leak site: Apr 2, 2026

About the victim

AI dossier — public-source company profile

United Medical Doctors (UMD) is an independent multi-specialty medical-surgical group operating 70+ locations across Southern California, covering 40+ specialties. The organization focuses on high-quality, compassionate outpatient care, patient satisfaction, and clinical research. They also conduct outpatient surgery and process improvement initiatives.

Industry: Multi-Specialty Outpatient Medical & Surgical Group
Address: Murrieta, California, USA
Employees: 201-500

Attack summary

Severity: critical — Confirmed data publication by ransomware group against a large multi-specialty medical-surgical group with 201-500 employees and 70+ locations, strongly indicating exfiltration of regulated patient health information (PHI/PII) at significant scale, which falls under HIPAA-regulated data.

The Insomnia ransomware group claims to have compromised United Medical Doctors and has published the data (disclosed status: data_published), indicating confirmed exfiltration of data from a large multi-specialty medical group with hundreds of employees and patients across 70+ locations.

critical

Data the group says was taken

AI dossier — extracted from the leak post

Patient medical records
Personal identifiable information (PII)
Clinical research data
Employee records
Financial and billing records
Insurance information

What the group claims

Functions as a comprehensive healthcare ecosystem—combining clinical care, surgical services, research innovation, and workforce development—all under one organization dedicated to improving community health in California

The leak post

captured from the group's site

Insomnia Human Verification What is 1 + 1 = ? Submit Nephrology Associates Hospitals &amp; Physicians Clinics Nephrology Associates, PA is a leading central Arkansas nephrology practice with seven highly trained physicians across seven locations. They provide compassionate kidney care, accept all insurances, and aim to create a welcoming environment for patients. Website: www.arnapa.com Revenue: $5 million Employees: 11-50 Location: Little Rock, Arkansas, USA Notified: 2026-4-6 METO Systems Industrial Machinery &amp; Equipment METO Systems designs and manufactures stainless-steel industrial material‑handling equipment for regulated industries. Products include lifts, blenders, transporters, and docking systems, they offer installation, training, customization, and support. Website: www.metosystems.com Revenue: $6 million Employees: 11-50 Location: Parsippany, New Jersey, USA Notified: 2026-3-31 United Medical Doctors Hospitals &amp; Physicians Clinics United Medical Doctors (UMD) is an independent multi‑specialty medical‑surgical group with 70+ Southern California locations and 40+ specialties. They focus on high‑quality, compassionate care, patient satisfaction, process improvemen…

Sources

Victim sitewww.***.com
Leak posthttp://i62huw7ve22rpyw6lnq3kmfump2dmsg4xpveec3ere73njwatrz74gad.onion/Company/Announce/

Source

Indexed 2 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.