Anthropic has warned some Claude users that their computers were infected with infostealer malware — including Vidar, Lumma, and Atomic Stealer — which allowed attackers to steal browser cookies and hijack login sessions to exploit their accounts. The company detected the activity, signed out compromised sessions, removed saved payment methods, and refunded any unauthorized charges. Affected users have been advised to remove all malware from their devices before re-adding payment information.
