Claude Clicked Send Instead of Continue, Because the Pixels Moved While It Thought

What happened

A researcher showed that Claude Computer-Use could be tricked by an attacker-controlled phishing page that swapped its Continue button for the Send button of an Outlook draft during the agent's reasoning pause, sending an arbitrary email. The issue was reported to Anthropic in October 2025, which said it was already tracking the risk. Anthropic later said its Cowork product checks that pixels haven't changed before acting.