What Is the “Noroboto” Attack, in Which a Document Looks Like an Ordinary Contract to Humans but AI Is Made to Read a Different Text by a “Fake Font”?

Drew Miller of Tritium Legal Technologies described Noroboto, an attack that embeds deceptive fonts in documents so humans see one text while AI systems extract another.

In tests, some AI platforms gave incorrect answers when only part of a contract was altered, showing how hidden font tricks can mislead document review.

The risk extends to legal review, invoices, audits, and procurement, where an AI could base decisions on text that never appears to people.

Proposed defenses include OCR checks and comparing the visible text, the file’s text, and the AI-processed text to ensure they all match.