2026 Arc Reinsurance Brokers — STORMOUS ransomware claim (May)
Data compromised
Unspecified corporate/reinsurance data per actor marketing
Technical writeup
Threat-intelligence feeds and security blogs indexed May 18, 2026 STORMOUS ransomware marketing against Arc Reinsurance Brokers (arc-reins.com), sometimes referenced alongside Fidelity United in actor posts. Initial coverage described a claimed massive data theft without a verified insurer notice or regulatory victim total at catalog time—BreachHistory classifies the entry as extortion-claimed reinsurance-sector exposure pending confirmation.
Root cause
STORMOUS ransomware group extortion claim