Was Miller & Stewart hit by ransomware?

Miller & Stewart was listed by the Sarcoma ransomware operation (United States), and stolen data was published on the group's leak site. Darkfield tracks this disclosure with the original leak post, screenshot and group context.

Who is the Sarcoma ransomware group?

Sarcoma is a ransomware operator tracked by Darkfield. See the full operator dossier for its known victims, sectors targeted, IOCs and leak-site infrastructure.

What data was leaked in the Miller & Stewart breach?

Sarcoma published data attributed to Miller & Stewart (~13 GB). Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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Miller & Stewart

Claimed by Sarcoma · listed 1 year ago

13 GB

Data size

13m

Age

since listed · data leaked

Status timeline

ListedJun 4, 2025
Data leakeddate unknown

At a glance

Group: Sarcoma
Status: Data leaked
Country: United States
Listed on leak site: Jun 4, 2025
Data size: 13 GB

About the victim

AI dossier — public-source company profile

Miller & Stewart is a financial services firm offering comprehensive accounting, tax, and advisory services to individuals, small to medium-sized businesses, and agencies. The firm emphasizes professional expertise, responsiveness, and quality client service.

Industry: Accounting & Financial Advisory Services

Attack summary

Severity: high — Confirmed exfiltration and publication of 13 GB of financial and tax data from a professional services firm. Such data typically includes PII, financial records, and sensitive business information for multiple clients.

Sarcoma claims to have exfiltrated 13 GB of data including files and SQL databases from Miller & Stewart. The group has published the data.

high

Data the group says was taken

AI dossier — extracted from the leak post

Client financial records
Tax documentation
SQL databases
Business files

What the group claims

Miller & Stewart Our firm provides outstanding service to our clients because of our dedication to three underlying principles: professionalism, responsiveness, and quality. Professionalism We believe our high standards, service, and specialized staff make a difference and are dedicated to ensuring every client receives personal attention. We also know how important it is to stay informed about new developments in tax law and other related topics. As such, we continually educate ourselves through professional organizations to improve our technical expertise and financial knowledge, as well as how to serve our clients better using state-of-the-art technologies. Responsiveness We provide comprehensive financial services to individuals, small to medium-sized businesses, and other agencies. Dedicated to serving client needs throughout the year - not just at tax time - we strive to respond quickly to any concerns our clients have. To see a listing of our services, please take a moment and look at our services page. Quality As trusted advisors, we are available to assist our clients at any time to provide insightful advice that enables them to make informed financial decisions. If you have any questions or want to learn more about how we can help you achieve your financial goals, don't hesitate to contact us today.Geo: Brazil - Leak size: 13 GB Archive - Contains: Files,SQL

Source

Indexed 1 year 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.

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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

June 4, 2025Miller & Stewart listed by Sarcomaon the group's public leak site

Data size: 13 GB

Other recent disclosures by Sarcoma

Sarcoma has been linked to 150 public victims on Darkfield. A sample of the most recent:

See the full Sarcoma dossier →

Sector and geography

Geographically, Miller & Stewart is reported in United States, a country with 11,033 ransomware disclosures in our corpus.

If your organisation is affected

A listing by Sarcoma means Miller & Stewart appeared on a ransomware extortion site and data attributed to it has been published. If this is your organisation, or a supplier you depend on, the priority is to confirm the intrusion and contain it before the window to act closes.

Engage your incident-response team and preserve forensic evidence before remediating — do not wipe affected systems first.
Force a password reset and revoke active sessions for exposed accounts; rotate any credentials, API keys or certificates that may have been in the stolen data.
Assess regulatory notification duties (GDPR, NIS2, sector regulators) — many carry a 72-hour reporting clock from awareness.
Report the incident to your national CERT, CISA (United States), as required for your jurisdiction.
Monitor for the data appearing on Sarcoma's leak site and across paste and breach channels, and brief downstream partners who may be exposed through you.

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.