GoKawiilResearcher demonstrates 60-80% prompt injection success against Claude Code's Auto Mode
A security researcher tested Anthropic's Claude Code Opus 5 in its default Auto Mode and found that a crafted website-summary request could hijack the agent into executing malicious code, succeeding in 60-80% of attempts on a small sample. The exploit tricks Claude into fetching a ZIP archive, writing its own Python decoder, and unknowingly running it inside an attacker-controlled folder where a poisoned struct.py file shadows Python's standard library and triggers code execution.