Disclosure context

About coinbasecartel

CoinbaseCartel is a ransomware group that emerged in September 2025 with financially motivated operations targeting organizations across multiple sectors and geographic regions. The group has demonstrated significant activity in a short timeframe, compromising at least 102 known victims primarily across the United States, United Arab Emirates, Germany, Canada, and Brazil. Their targeting patterns show a preference for technology companies, financial services organizations, manufacturing entities, and consumer services businesses, suggesting an opportunistic approach focused on organizations likely to have both valuable data and the financial resources to pay ransoms. Given the group's recent emergence and limited public documentation from established threat intelligence sources, details regarding their specific attack methodologies, infrastructure, and organizational structure remain largely unconfirmed by major cybersecurity firms or law enforcement agencies. The group appears to maintain active operations as of late 2025, though comprehensive analysis of their tactics, techniques, and procedures awaits further investigation and reporting by established threat intelligence organizations. The group has been linked to 176 public disclosures across our corpus. First observed on a leak site on September 15, 2025; most recent post May 16, 2026. The operation is currently active.

Also tracked as: coinbase cartel.

Timeline of this disclosure

May 11, 2026Cass information Systems listed by coinbasecartelon the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Business Services sector, which has 2,640 disclosures indexed across all operators we track. Geographically, Cass information Systems 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

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Cass information Systems

Claimed by coinbasecartel · listed 10 days ago

Age

since listed · data leaked

Status timeline

Listed
May 11, 2026
Data leaked

At a glance

Group: coinbasecartel
Status: Data leaked
Country: US
Sector: Business Services
Listed on leak site: May 11, 2026

About the victim

AI dossier — public-source company profile

Cass Information Systems is a US-based provider of integrated payment and information management solutions headquartered in St. Louis, Missouri. The company specializes in freight audit and payment, utility bill management, waste invoice management, and MRO expense management for large enterprises globally. It manages approximately $94 billion in annual disbursements, processing over 51 million invoices per year across 185 countries, supported by its own chartered bank, Cass Commercial Bank.

Industry: Financial Technology & Business Process Outsourcing (Accounts Payable Automation)
Address: 12444 Powerscourt Drive, St. Louis, MO 63131, USA
Employees: 1000+
Founded: 1906

Attack summary

Severity: critical — Cass Information Systems processes $94 billion in annual disbursements and handles financial invoice and payment data for large corporations globally. A confirmed data publication by the threat actor implicates large-scale financial records, enterprise client PII, and accounts payable data — constituting regulated financial data at scale across hundreds of corporate clients.

The coinbasecartel group claims to have attacked Cass Information Systems and has published data ('data_published' status), though no specific ransom demand or data volume was stated in the post. The nature of the exfiltration — whether encryption, data theft, or both — is not explicitly detailed in the truncated leak post.

critical

Data the group says was taken

AI dossier — extracted from the leak post

Financial transaction records
Freight invoice data
Utility billing data
Accounts payable records
Enterprise client data
Payment processing information
Corporate spending analytics

Original description

AI-summarised, not from the leak post

Cass Information Systems is a US-based company specializing in payment and information services. It provides freight invoice processing, auditing, and payment solutions, along with utility and telecom expense management. Operating primarily in the financial technology and business process outsourcing industry, Cass serves large corporations across North America and globally, helping clients manage and analyze invoice data to optimize spending and operational efficiency.

The leak post

captured from the group's site

System Breach • Coinbasecartel We are looking for new partners/insiders. Send us a message to dicuss We are looking for new partners/insiders. Send us a message to dicuss CRITICAL ANNOUNCEMENTS &times; Contact Update We have changed our contact method. We now exclusively use qTox Messenger for all communications. SimpleX and Session have been discontinued. Our Tox ID: A7580331D4D16453CCE86D7ADFBCF0CEED0D0D1AEA8F4DBEEBCA9E3B46308F260DE9B41BD838 TO APTIM You may have noticed the sudden, heavy silence. The corporate VPNs are dead. We have been the silent architects of your network for the past three weeks. While your &#34;elite&#34; investigators from Mandiant sat in your logs, we sat directly beside them burning through over a hundred of your corporate identities like disposable tools. we have had your entire network and internal protocols. HOW LONG WILL YOU KEEP YOUR THOUSANDS OF FIELD WORKERS LOCKED OUT? We have successfully exfiltrated the most sensitive engineering data held by any firm in your sectors We hold the complete Navisworks 3D models, P&amp;ID diagrams, and maintenance logic for your major energy plants. This includes the granular Honeywell DCS controller logic. We know…

Sources

Victim sitecassinfo.com
Leak posthttp://fjg4zi4opkxkvdz7mvwp7h6goe4tcby3hhkrz43pht4j3vakhy75znyd.onion/companies/cass

Source

Indexed 10 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.