providing an initial electronic file as input to an initial ML model for processing, wherein content of the initial electronic file is defined by the at least one marker, and wherein an output of the initial electronic file is determined by the initial ML model according to an initial processing strategy, the output being exclusive only for electronic files comprising the at least one marker;

feeding the output of the initial electronic file as input to a reverse classifier that generates a second electronic file as its output;

obtaining the second electronic file, wherein the second electronic file represents content that causes a second ML model to determine an output for the second electronic file according to a first processing strategy; and

embedding, in the second electronic file, the at least one marker that, only when detected by the second ML model, causes the output of the second electronic file to be determined according to a second processing strategy, the second processing strategy being unrelated to the first processing strategy and deterministically defined by the at least one marker.