Securityweek

Anthropic force-logs-out Claude users hit by infostealer-based session theft

Anthropic notified affected customers that malware on their own computers had stolen active Claude login sessions, letting attackers rack up unauthorized usage and charges. The company responded by signing out compromised sessions, removing saved payment cards, and refunding the fraudulent charges. Anthropic clarified the breach originated from infostealer malware on users' devices, not from any compromise of its own systems.