Hackers hijack Brazil’s emergency alert system and send ‘misanthropy’ to millions of phones
The TL;DR
Brazil’s civil defense alert system was hacked, sending fake alerts with the name “misantropi4” to millions of phones before the platform was shut down.
Hackers breached Brazil’s social security alert system overnight, sending fake “Extreme Warning” notices containing the word “misanthropy4” to millions of cell phones across at least seven states. The Civil Defense Alert platform was released online at 1:30 a.m. Saturday after the Ministry of Regional Development and Coordination confirmed the intervention.
State Police have been called in to investigate. No time has been given as to when the stadium will be restored.
The first unauthorized warning was registered around 11:40 pm on Friday, 19 June, in Paraná. In a few hours, the same emergency sound, the kind that overrides silent mode and removes anything on the screen, reached phones in São Paulo, Rio de Janeiro, Brasília, Bahia, Pará, Mato Grosso do Sul, and Acre.
National Secretary of Defense and Public Protection Wolnei Wolff told a press conference that 10 alerts were tracked in various states of Brazil, most were sent by Cell Broadcast and at least one by SMS. The total number of affected phones has not been officially disclosed, although the German outlet Ad-hoc-News reported an estimate that around 30 million people were reached.
“It is difficult to say whether one or more people are involved in this crime,” Wolf said. He added that the incident “It is very bad for the system, given that we are dealing with people’s safety when we issue a warning.“
Phones shown “Defesa Civil: misantropi4,” with the last letter “a” in the Portuguese name “misanthropia” was replaced by the number 4, the usual position in leetspeak. Misantropia translates to misanthropy, which means hatred or aversion to humanity.
No hazard warnings accompanied the message, but the use of the worst-case alert category, reserved for imminent natural disasters, caused quite a stir. Receivers in all seven districts were awakened by the sound of the emergency.
Wolff confirmed that the attackers were able to regain access after the initial blocking attempt. The stadium was finally shut down completely at 1:30 a.m. The program will remain suspended until all digital security conditions are re-established, according to the department.
Brazil’s Mobile Broadcasting System is new. It was approved by the telecommunications regulator Anatel in 2022, tested in 11 cities from August 2024, and expanded to cover the entire national territory in October 2025.
The technology broadcasts alerts to all devices within range of a cell tower without requiring phone numbers or prior registration. The four operators that deliver the service, Algar, Claro, TIM, and Vivo, participated in the night response along with Anatel.
The vulnerability that was exploited in the attack has not been publicly disclosed, and the investigation is ongoing. Security researchers have noted that mobile broadcast systems around the world lack cryptographic authentication, meaning devices cannot independently verify whether an alert was actually sent by security authorities.
Academic research as of 2019 has shown that fake alerts can be broadcast using relatively inexpensive equipment, including software-defined radios. Whether the Brazilian attack used a central platform, as the government’s statement said, or a secret transmitter was not clear.
The person claiming responsibility for the attack posted on X (formerly Twitter) before the post was removed by the platform, according to Brazilian tech outlet TecMundo. The Federal Police have not confirmed that this person is the real suspect.
This incident matches the pattern of warning systems for vulnerable infrastructure due to basic attack sites. In Taiwan last month, a 23-year-old student caused emergency braking on four high-speed trains using a laptop computer and a cheap software-defined radio, using cryptographic keys that hadn’t been changed in 19 years. The European Commission was breached in March with a poisoned security tool, resulting in 92 gigabytes of stolen data.
The immediate concern for Brazil is the collapse of public trust. The Mobile Broadcasting System is designed to save lives during floods, landslides, and severe weather conditions.
If citizens learn to associate emergency sounds with pranks as real warnings, they may ignore future warnings when a real disaster occurs. That risk, more than any technological vulnerability, is the lasting damage of hacking that has awakened the country with one unusual word.
