Hackers are stealing Claude tokens from subscribers

Hackers are stealing Claude tokens from subscribers. Last month, Grant De Swardt, an independent AI consultant in East Sussex, U.K., noticed his account was consuming tokens even though he wasn't working. Anthropic has since warned users about hackers. The company found the culprit: A compromised Claude session key was used to mint unauthorized Claude Code OAuth tokens. This type of theft could have gone on for months undetected because account support tracks total usage but not itemized usage. Other users shared similar experiences, including one who claimed their account burned through its max tokens every day for three days without them using it at all.