Anthropic locks out Claude users after infostealers hijack login sessions

Anthropic began locking users out of Claude after an active infostealer campaign—attributed to malware families including Vidar, Lumma, StealC, RedLine, Acreed and Atomic Stealer—stole browser session cookies and credentials, allowing account hijacks and unauthorized charges; Anthropic invalidated sessions, removed saved payment methods, refunded charges, and advised victims to clean malware, rotate passwords, enable 2FA, and re-establish sessions only after removal of the infection.