ASTM Group Listed by coinbasecartel Ransomware Group: Ransomware Claim — What’s Alleged & What To Do
ASTM Group has been listed by the coinbasecartel ransomware group, with internal files reported exfiltrated in an attack disclosed on April 18, 2026. The number of people affected remains undisclosed; anyone connected to the organisation should verify whether their information was exposed and take protective steps.
What happened
On April 18, 2026, the ASTM Group appeared on a listing attributed to the coinbasecartel ransomware group. The only confirmed detail is that internal files were allegedly exfiltrated during a ransomware attack. No figure has been released for the number of individuals whose data may be involved, and no further technical description of the intrusion has been made public.
Inside coinbasecartel
Coinbasecartel is a ransomware operation that has publicly claimed responsibility for intrusions at multiple organisations. Like other groups of its kind, it typically combines file encryption with the threat of data publication on a leak site. The listing of ASTM Group constitutes the group’s own claim; independent confirmation of the data’s authenticity or volume has not been reported.
ASTM Group and its sector
ASTM Group operates in the infrastructure and transportation sector, managing large-scale concession assets that generate extensive operational records. Organisations of this type routinely maintain employee records, supplier contracts, technical specifications and financial documentation. A breach involving such material can affect both internal processes and any third parties referenced in the files.
What was likely exposed
The only information released states that internal files were exfiltrated. The precise categories of data contained in those files have not been disclosed. While infrastructure companies commonly store personnel details, contractual information and engineering documents, the actual contents remain unconfirmed.
What's at stake
Exposed internal files can reveal operational dependencies, commercial arrangements or personal identifiers that may be misused for fraud, targeted phishing or further criminal activity. For the organisation, the incident adds the cost of investigation, potential regulatory scrutiny and the need to restore systems without public clarity on the data’s scope.
If your data was in this claimed breach
Monitor accounts for unusual activity and consider changing passwords for any services linked to ASTM Group or its partners. Enable multi-factor authentication where available. Readers can run a free exposure scan of their email address against known breach data to check for appearances in previously published datasets.
AICompiled with AI assistance from public sources and published under our editorial standards.
How this breach connects
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Read GalaxyWarden’s full analysis of the ASTM Group Listed by coinbasecartel Ransomware Group →
Publicly posted by coinbasecartel — unverified claim, pending independent verification
Breach listings — particularly those originating from ransomware or leak sites — are third-party claims that may be unverified, incomplete, or inaccurate. A listing does not by itself confirm that a breach occurred or that any specific data was exposed. Severity is an automated assessment, not a definitive rating. Verification status is shown where available.
Attributions to threat groups and methods reflect public reporting and, in some cases, unverified claims made by the groups themselves; they may be incomplete or later revised. Recent Breaches and GalaxyWarden are independent and are not affiliated with, and do not endorse, any company or group named on this page. This information is aggregated from public sources for awareness only and is not legal, security, or investment advice.