Anthropic flags Claude session-cookie replay by infostealers

Anthropic notified affected Claude users that infostealer malware had copied browser session cookies and attackers replayed them to use paid accounts, according to reporting on the notification. The company named six stealer families, signed affected accounts out, removed saved payment methods and refunded identified charges. The report says Anthropic did not disclose an account count or whether replayed sessions accessed connected apps or conversation history.