2023 HWL Ebsworth — ALPHV/BlackCat ransomware; ~4TB claimed
Data compromised
Actor-claimed employee CVs/IDs, financial/accounting data, client documents, credit-card information, network maps — firm acknowledged cyber incident; later litigation/injunction activity reported in Australian coverage
Technical writeup
Verified firm acknowledgment of a cyber incident after ALPHV/BlackCat posted in late April 2023 claiming exfiltration from HWL Ebsworth. Contemporary reporting (Guardian, AFR timelines) said the group claimed roughly 4TB including employee and client materials; the firm’s public cyber-incident page confirmed awareness of the ALPHV/BlackCat forum claim. Subsequent Australian coverage described ransom demands, partial publication, and court injunctions restraining further disclosure. No single regulator-attested individual count is used here (recordsAffected 0). Separate from the University of Western Australia’s 2026 Callista incident — a July 2026 search did not surface a clear joint “HWL + UWA sued” filing tied to a new shared breach event beyond historical HWL litigation and the distinct UWA notice.
Root cause
ALPHV/BlackCat ransomware intrusion and data exfiltration claim against Australian law firm HWL Ebsworth