---
title: "Hidden instructions target the AI systems of Brazilian courts — Marsanne Studio AI watch"
description: "Several Brazilian courts have detected hidden commands in case filings aimed at manipulating their AI systems, and are penalising those responsible."
url: "https://marsanne.studio/en/ai-watch/hidden-instructions-target-the-ai-systems-of-brazilian-ae8945/"
lang: "en"
---

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Analysis · 1 October 2026

# Hidden instructions target the AI systems of Brazilian courts

Original title, in French: “Des instructions cachées visent les IA des tribunaux brésiliens”

**Publication**

ActuIA (France)

**Author**

Stephane Nachez

**Published on**

1 October 2026 · read in the page structured data · updated on 1 October 2026

## Summary

In Brazil, at least four courts have since May identified injections of hidden instructions in case filings, intended to steer the courts' artificial intelligence systems. The Supremo Tribunal Federal (Maria platform), the Superior Tribunal de Justiça (Logos engine) and labour courts (Galileu system) detected these attempts and imposed fines ranging from 10% of the value of the dispute to 30,000 reais, and referred the matter to the Brazilian Bar Association and the public prosecutor's office. The National Council of Justice (CNJ), which regulates the use of AI through Resolution 615/2025, published non-binding technical recommendations in June for filtering filings and tracing such attempts. In France, the Cour de cassation considers the use of AI to analyse parties' submissions in its April 2025 report.

Summary based on the full text of the article.

[Read the article on ActuIA →](https://www.actuia.com/actualite/des-instructions-cachees-visent-les-ia-des-tribunaux-bresiliens/)

## Figures cited

-   3,242 reais
    
    Fine imposed by the STF for hidden instructions
    
    Brazil, rapporteur's vote at the STF, 25 September 2026
    
    > « À ce barème, l'amende retenue dans le vote du rapporteur représente 3 242 reais, soit un cinquième du plafond que le paragraphe 5 permettait d'atteindre. »
    
-   247 appeals
    
    Appeals grouped by theme by VitorIA in 2023
    
    STF, 2023
    
    > « cette année-là, au moins 247 recours rapprochés sur un seul thème »
    
    Source: STF
    
-   10 % of the value of the dispute
    
    Fine for bad-faith litigation in Parauapebas
    
    Regional Labour Court, Parauapebas, May 2026
    
    > « le juge a condamné les avocates à une amende de 10 % de la valeur du litige et saisi l'OAB »
    
-   30,000 reais
    
    Fine imposed in Salvador for an act offensive to the dignity of the court
    
    4th Chamber of the Regional Labour Court of the 5th Region (Bahia), July 2026
    
    > « La sanction : 30 000 reais pour acte attentatoire à la dignité de la justice, 10 % de la valeur actualisée du litige pour litigance de mauvaise foi, et saisine de l'OAB, de la police fédérale et du MPF. »
    

## Classification

**Country**

Brazil, France

**Company size**

All sizes

**Industries**

Government and local authorities

**Companies**

Maria Shield (supplier), Conseil national de justice (CNJ) (cited), Galileu (supplier), VitorIA (supplier), OWASP (cited), Superior Tribunal de Justiça (deploys AI), Logos (supplier), Supremo Tribunal Federal (deploys AI), Cour de cassation (cited)

**Keywords**

prompt injection, justice, generative artificial intelligence, regulation, Brazilian courts, cybersecurity

Entry written by Marsanne Studio from the cited article, with the help of an AI model (claude-sonnet-5). The rights to the article and its illustrations belong to ActuIA and its author. Entry translated from French by Claude Sonnet 5.5.