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

May 7, 2026MSB General Contractors listed by Sarcomaon the group's public leak site

Data size: 66 GB

Sector and geography

This disclosure adds to ransomware activity in the Commercial & Residential Construction sector. Geographically, MSB General Contractors is reported in USA.

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

MSB General Contractors

Claimed by Sarcoma · listed 13 days ago

66 GB

Data size

13d

Age

since listed · data leaked

Status timeline

Listed
May 7, 2026
Data leaked

At a glance

Group: Sarcoma
Status: Data leaked
Country: USA
Sector: Commercial & Residential Construction
Listed on leak site: May 7, 2026
Data size: 66 GB

About the victim

AI dossier — public-source company profile

MSB General Contractors (MSB, Inc.) is a licensed general contracting firm based in the USA specializing in disaster recovery services for residential and commercial clients. The company manages recovery projects across a range of emergencies, offering support from initial response through project completion. They can be reached at 760-751-5050 and hold contractor license #450395.

Industry: Disaster Recovery & General Contracting

Attack summary

Severity: high — 66 GB of data has been confirmed exfiltrated and published by the threat actor. Disaster recovery contractors handle sensitive client PII, insurance records, and residential/commercial property data, representing significant business and potentially regulated data exposure at scale.

The Sarcoma ransomware group claims to have exfiltrated 66 GB of data from MSB General Contractors, with the disclosure status listed as data_published, indicating the stolen data has been released or made available.

high

Data the group says was taken

AI dossier — extracted from the leak post

Project files
Client records
Completed project documentation
Business correspondence
Internal company data

What the group claims

MSB General Contractors specializes in disaster recovery services, offering support and solutions for clients affected by various emergencies. Their focus is on ensuring timely and efficient recovery processes for both residential and commercial projects

The leak post

captured from the group's site

Site: https://gyf.com.ar/ Industry: Business Services GEO: Argentina 
Site: www.propanelevac.ca Industry: Gas Stations, Retail GEO: Canada 
Site: www.mecmatica.it Industry: Provider of software solutions GEO: Italy 
Site: bedachungen-soellner.de Industry: Commercial & Residential Construction GEO: Germany 
Site: charterindustrial.com Industry: Industrial Machinery & Equipment GEO: USA 
Site: msbuilders.com Industry: Commercial & Residential Construction GEO: USA 
Site: thermofin.de Industry: Building Materials GEO: Germany 
Site: miamimanagement.com Industry: Business Services GEO: USA 
Site: kwg-senftenberg.de Industry: Business Services GEO: Germany 
Site: f1-generation.com Industry: Apparel & Accessories Retail GEO: Germany 
Site: inoxlaghi.com Industry: Industrial Machinery & Equipment GEO: Italy 
Site: maselli.com Industry: Manufacturing innovative optical technology GEO: Italy 
Site: metroheatingandair.com Industry: Commercial & Residential Construction GEO: USA 
Site: hv.com.co Industry: Food & Beverage GEO: Colombia 

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Propane Levac inc. specializes in the distribution of propane across Ontari…

Screenshot of the leak post

Leak screenshot for MSB General Contractors

Sources

Victim sitemsbuilders.com
Leak posthttp://sarcomawmawlhov7o5mdhz4eszxxlkyaoiyiy2b5iwxnds2dmb4jakad.onion

Source

Indexed 13 days 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.