Disclosure context

About Sarcoma

Sarcoma is a relatively new ransomware group that emerged in October 2024, operating with apparent financial motivations and demonstrating a broad international targeting approach with at least 140 documented victims across multiple countries and industry sectors. The group's origin and affiliations remain unclear due to its recent emergence, with no publicly documented connections to established ransomware families or confirmation of whether they operate as an independent entity or through a Ransomware-as-a-Service model. Limited public information is available regarding Sarcoma's specific attack methodologies, initial access vectors, or technical capabilities, though their targeting patterns suggest opportunistic rather than highly selective victim selection across diverse industries including manufacturing, business services, agriculture and food production, and technology sectors. The group has shown a particular focus on victims in the United States while also maintaining operations against targets in Italy, Canada, Germany, and Australia, though no specific high-profile attacks or record ransom demands have been publicly documented by major security firms or law enforcement agencies. Given the group's recent emergence in late 2024, Sarcoma appears to remain active with no reported law enforcement disruptions or confirmed rebranding activities at this time. The group has been linked to 150 public disclosures across our corpus. First observed on a leak site on October 9, 2024; most recent post May 12, 2026. The operation is currently active.

Also tracked as: Sarcoma Ransomware Group.

Timeline of this disclosure

July 23, 2025Sanderling Healthcare listed by Sarcomaon the group's public leak site

Data size: 587 GB

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, Sanderling Healthcare 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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Sanderling Healthcare

Claimed by Sarcoma · listed 10 months ago

587 GB

Data size

10m

Age

since listed · data leaked

Status timeline

Listed
Jul 23, 2025
Data leaked

At a glance

Group: Sarcoma
Status: Data leaked
Country: United States
Sector: Healthcare
Listed on leak site: Jul 23, 2025
Data size: 587 GB

About the victim

AI dossier — public-source company profile

Sanderling Healthcare, founded in 2009 by Dr. Jerome S. Tannenbaum, is a healthcare company specializing in the design and construction of dialysis clinics and hospital facilities. The company focuses on cost-effective and efficient facility development, with a track record of approximately 100 dialysis clinics built across the United States.

Industry: Healthcare Facilities & Dialysis Clinic Design/Construction
Founded: 2009

Attack summary

Severity: high — Healthcare sector victim with confirmed exfiltration of 587 GB of data including email and database records. Healthcare data typically includes patient PII and medical information subject to HIPAA and other regulations, making this a significant breach despite no explicit proof files listed.

The Sarcoma group claims to have exfiltrated 587 GB of data from Sanderling Healthcare, including files, email archives (Exchange), and databases. The post does not explicitly state whether encryption occurred alongside the data theft.

high

Data the group says was taken

AI dossier — extracted from the leak post

Email archives (Exchange)
Database records
Company files

What the group claims

Sanderling Healthcare Sanderling Healthcare was founded in 2009 by Dr. Jerome S. Tannenbaum to further one of his personal missions for healthcare – to lower the cost, and speed the construction, of healthcare facilities. As a nephrologist and successful entrepreneur, Dr. Tannenbaum had spent years perfecting his dialysis clinic designs. Known for counting every step made by his nurses and patient care technicians, and having developed roughly 100 dialysis clinics across the country, Dr. Tannenbaum perfected the design of the modern day dialysis clinic. Among the many benefits of working with Sanderling, is the peace of mind to know exactly what a new or expanded hospital facility will cost, and when it will be ready for occupancy.Geo: USA - Leak size: 587 GB Archive - Contains: Files,Excahnge,Bases

Source

Indexed 10 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.