False Civil Defense alert: what is known about messages sent to cell phones in several cities

Rio de Janeiro resident shows extreme alert received on his cell phone with the word "misanthropy".
Reproduction
Residents from different regions of the country reported having received, between the night of Friday (19) and the early hours of this Saturday (20), extreme sound alerts and text messages attributed to the Civil Defense. The case drew attention due to its unusual content: on some cell phones, only the word "misanthropy" appeared; in others, disjointed messages with writing errors.
To date, there is no official confirmation about what caused the shots. Authorities in Paraná and São Paulo stated that they did not send the alerts and reported that they were investigating the origin of the messages.
According to the Civil Defense of Paraná, the agency contacted the National Civil Defense and Anatel to investigate the case. The São Paulo Civil Defense reported that the Cell Broadcast tool, used to send severe and extreme alerts, is managed by Anatel and said it also contacted the agency.

Source: G1