This paper seeks to identify vulnerabilities of journalism that have been exploited by interest groups capable of "hacking" the productive routines of newsrooms to spread disinformation. From the analysis of events in Brazilian politics between 2018 and 2022, we pointed to a) cases in which the valorization of high-ranking sources allowed the dissemination of false allegations and generated raw material for propaganda in favor of the former president; b) in which the principle of objectivity resulted in declaratory journalism or false equivalences; and c) in which the relevance given to controversies in social networks as newsworthy topics resulted in the amplification of extreme right-wing ideas in the news. We conclude stressing the necessity of a review of the principles, values and professional practices of journalism, so that their aspects vulnerable to exploitation by agents that disseminate disinformation are updated