The present invention relates to the detection of malicious software in electronic documents and comprises: detecting an executable code in the electronic document provided to a client module; extracting information from the electronic document comprising the executable code and metadata of the electronic document; creating a binary vector associated with the electronic document; comparing, in a classifier module (200), the binary vector with one or more groups of vectors previously classified and stored in a database (400); classifying the vector in one of the groups, where each group has associated therewith a verdict about the presence of malicious software; and determining that the document contains malicious software depending on the verdict associated with the group in which its associated vector has been classified.