Ransomware victim disclosure
← All victimsTab Service
Claimed by coinbasecartel · listed 10 days ago
Status timeline
- Listed
May 11, 2026
- Data leaked
At a glance
- Group
- coinbasecartel
- Status
- Data leaked
- Country
- DE
- Sector
- Business Services
- Listed on leak site
- May 11, 2026
About the victim
AI dossier — public-source company profileTab Service Company is a US-headquartered back-office outsourcing firm with over 65 years of operation, serving 2,500+ clients across regulated industries including healthcare, higher education, fintech, banking, and legal. The company provides tax form processing and e-filing (1099, 1098-T), document scanning, print and mail, data entry, digital mailroom, and survey services. It holds SOC 2 certification, HIPAA compliance, and is an IRS Authorized E-File Provider, indicating it handles sensitive regulated data at scale.
- Industry
- Back-Office Outsourcing & Document Processing Services
- Founded
- 1959
Attack summary
Severity: critical — Tab Service processes regulated data at scale for thousands of clients across healthcare, fintech, banking, higher education, and legal sectors — including HIPAA-covered health data, IRS tax documents, and financial records. A confirmed data publication event at this type of organization implies likely exfiltration of sensitive PII and regulated financial/medical records affecting potentially millions of end-users across 2,500+ client organizations.The coinbasecartel ransomware group claims to have compromised Tab Service and has published data (disclosed status: data_published); however, the leak post contains no substantive detail about the nature of the attack, whether encryption or exfiltration occurred, or what specific data was taken.
Data the group says was taken
AI dossier — extracted from the leak post- Tax documents (1099, 1098-T forms)
- Client records from regulated industries
- Healthcare data (HIPAA-covered)
- Financial/banking records
- Scanned paper documents
- Survey data
- Physical mail contents (digital mailroom)
- Data entry records
Original description
AI-summarised, not from the leak postN/A
The leak post
captured from the group's siteSystem 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 × 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 "elite" 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&ID diagrams, and maintenance logic for your major energy plants. This includes the granular Honeywell DCS controller logic. We know…
Sources
Source
Indexed 10 days agoThis 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.
