Disclosure context

About sinobi

Based on the limited publicly available information, Sinobi appears to be a recently emerged ransomware operation first observed in July 2025, with financial motivations evidenced by their targeting of 268 victims across multiple sectors. The group's origin and specific affiliations remain undocumented in public threat intelligence reporting, and there is no confirmed information regarding whether they operate as a Ransomware-as-a-Service model or as an independent entity. Their attack methodology and technical capabilities have not been extensively documented by major security research organizations, though their targeting patterns suggest a broad opportunistic approach rather than highly selective operations. The group demonstrates a preference for targeting organizations in the United States, India, United Kingdom, Canada, and Italy, with a focus on manufacturing, healthcare, construction, and technology sectors, suggesting they may exploit common vulnerabilities across these industries rather than deploying sophisticated, sector-specific attack vectors. No major high-profile campaigns or significant law enforcement actions against Sinobi have been publicly reported by CISA, FBI, or established threat intelligence firms. Given the recent emergence timeline and lack of extensive public documentation, the group's current operational status and long-term trajectory remain unclear, though the substantial victim count suggests continued activity as of the last available reporting period. The group has been linked to 274 public disclosures across our corpus. First observed on a leak site on July 5, 2025; most recent post May 8, 2026. The operation is currently active.

Timeline of this disclosure

March 19, 2026Amerinational Management Services (AMS) listed by sinobion 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, Amerinational Management Services (AMS) 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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Amerinational Management Services (AMS)

Claimed by sinobi · listed 2 months ago

Age

since listed · data leaked

Status timeline

Listed
Mar 19, 2026
Data leaked

At a glance

Group: sinobi
Status: Data leaked
Country: United States
Sector: Not Found
Listed on leak site: Mar 19, 2026

About the victim

AI dossier — public-source company profile

Amerinational Management Services (AMS) specializes in providing comprehensive business solutions for martial arts schools, including marketing, software, and tuition management services. Their flagship product is ATLAS Martial Arts Software, complemented by lead funnel websites, merchant accounts, and after school/summer camp program management. With over 40 years of experience, AMS targets martial arts school owners seeking to enhance business operations and profitability.

Industry: Martial Arts Business Management & Software Services

Attack summary

Severity: high — Data has been published (disclosed status: data_published), indicating confirmed exfiltration. AMS handles merchant accounts and tuition management for numerous martial arts schools, meaning financial and potentially personal data of school owners and their students could be at risk at scale.

The group 'sinobi' has disclosed data pertaining to Amerinational Management Services under a 'data_published' status, indicating exfiltration and publication of company data. No specific details on encryption or the precise volume of exfiltrated data were stated in the leak post.

high

Data the group says was taken

AI dossier — extracted from the leak post

Business management records
Tuition management data
Merchant account information
Client (martial arts school) records
Marketing data

What the group claims

Amerinational Management Services, Inc. specializes in providing comprehensive business solutions for martial arts schools, including marketing, software, and tuition management services. Their offerings encompass ATLAS Martial Arts Software, lead funnel websites, merchant accounts, and after school/summer camp programs. The company targets martial arts school owners looking to enhance their business operations and profitability. With over 40 years of experience, AMS is dedicated to helping martial arts professionals achieve their goals through effective management and marketing tools.

Sources

Leak posthttp://sinobi6ftrg27d6g4sjdt65malds6cfptlnjyw52rskakqjda6uvb7yd.onion/leaks/69b99a6b6387a4c9a2867265

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.