Detecting fake videos

In one embodiment, a method includes accessing a plurality of verified videos depicting one or more subjects, generating, based on the verified videos, a plurality of verified-video feature values corresponding to the subjects, generating, using one or more video transformations based on the verified videos, a plurality of fake videos, generating, based on the fake videos, a plurality of fake-video feature values, training a machine-learning model to determine whether a specified video is a genuine video, wherein the machine-learning model is trained based on the verified-video feature values and the fake-video feature values. The machine-learning model may be trained to classify the specified video in a genuine-video class or a fake-video class, and the machine-learning model maybe trained based on an association between a genuine-video class and the verified-video feature values and an association between a fake-video class and the fake-video feature values.