The akira ransomware group listed High Grade Materials on its data leak site on 2025-05-28. Country: US Sector: Manufacturing Domains named: highgradematerials.com Claim as published on the leak site: High Grade Materials is a Michigan-based company specializing in concrete and concrete-related products. We are going to upload about 20 GB of corporate data. A lot of em ployee information (DOB, passport number, address, phone and so o n), detailed financial data (audits, payment details, reports, in voices), contracts and agreements, death/birth certificates, NDAs , etc.