Brazil’s Army Runs Cyber Defense Drill Ahead of Election

The Brazilian Army coordinated, from Monday (21) through this Friday (25), the eighth edition of the Cyber Guardian exercise, a digital defense drill held just days before the first round of the 2026 election, set for October 4. The exercise ran simultaneously in Brasília and six other state capitals — Belém, Manaus, Curitiba, Recife, Rio de Janeiro and São Paulo.

How the exercise worked

Described by the Army as one of the most comprehensive cyber defense drills in the Southern Hemisphere, Cyber Guardian 8.0 brought together roughly 1,300 participants from 300 organizations, including the armed forces, government agencies, regulators and operators of critical infrastructure in energy, water supply, telecommunications and finance, plus representatives from 14 countries.

During the exercise, teams faced complex, coordinated cyberattack scenarios designed to test procedures, contingency plans and response mechanisms for incidents that could affect essential public services.

Context: warnings about foreign interference

The drill took place amid warnings from experts and Brazil’s intelligence agency (Abin) about possible foreign interference in the election. An Abin report, drafted in August and reported by Folha de S.Paulo, rated the possibility of outside interference at a “critical” level and tied the risk to the current U.S. administration’s stated priority of reasserting its influence in Latin America.

Alongside the Army’s exercise, Brazil’s Superior Electoral Court (TSE) has also been testing the systems used to publish and tally election results, running simulations to validate the technology used for the vote.