While there has always been discourse seeking to discredit feminism and its proposals using false arguments, as the movement has gained ground, the effort to discredit it has increased. Based on cases reported by the media websites Maldita.es, in its section Maldito Feminism, Newtral.es and Efe Verifica, we point out the important presence of anti-feminist content in the disinformation present in social media. We analyse the underlying ideology and the reasons why this discourse is particularly damaging to the feminist movement (...) today and to society in general, as new technologies make disinformation even more dangerous. We conclude our research by drawing a parallel between this phenomenon and Susan Faludi's analysis of the anti-feminist reaction in the 1980s, looking at the new challenges facing feminism in this fight against post-truth. (shrink)