The disclosed computer-implemented method for detecting attempts to transmit sensitive information via data-distribution channels may include (1) identifying an attempt to transmit a file through a data-distribution channel, (2) comparing, using an image-matching technique, the file with at least one known sensitive file that is both stored in an image format and protected by a data-loss-prevention policy, (3) determining, based on the results of the image-matching technique, that the file violates the data-loss-prevention policy, and (4) performing a security action in response to determining that the file violates the data-loss-prevention policy. Various other methods, systems, and computer-readable media are also disclosed.