Expert warns this dangerous Microsoft Word worm can burrow into Copilot and cause havoc — here's what we know

A security researcher demonstrated a Word document worm that exploits Microsoft 365 Copilot by hiding instructions as white text, causing Copilot to alter documents and propagate the malicious prompt silently. Despite Microsoft's mitigations over 144 days, the attack remains reproducible, highlighting a persistent vulnerability in Copilot's handling of hidden text prompts.