The popular encrypted messaging and chat app WhatsApp played a key role in the election of Brazilian President Jair Bolsonaro in 2018. The present study builds on this knowledge and showcases how the app continued to be used in a governmental operation spreading false and misleading information popularly known in Brazil as the Office of Hatred (OOH). By harnessing in-depth expert interviews with documentarians of the office’s daily operations—researchers, journalists, and fact-checkers (N = 10)—this study draws up a chronology of the OOH. Via this methodological approach, we trace and chronologize events, actions, and actors associated with the OOH. Specifically, findings (a) document the rise of antipetismo and disinformation campaigns associated with attacks on the Brazilian Worker’s party from 2012 until the election of Bolsonaro in 2018, (b) describe the emergence of the OOH at the heels of the election and subsequent radicalization in WhatsApp groups, (c) provide an overview of the types of disinformation that are spread on the app by the OOH, and (d) illustrate how the OOH operates by mapping key actors and places, communicative strategies, and audiences. These findings are discussed in light of ramifications that government-sponsored forms of disinformation might have in other antidemocratic polities marked by strongman populist leadership.