Microsoft Copilot for Word Can Copy Hidden Prompts Into New Documents

Hidden instructions in a Word document can make Microsoft 365 Copilot rewrite figures in a report, then copy the same instructions into the finished file. Håkon Måløy disclosed the technique on July 28, 144 days after reporting it to Microsoft.

In his proof of concept, the internally generated file triggered the same behavior when it was used in a second Copilot drafting session.

Måløy's