Steganography is the practice of hiding data inside normal-looking content such as images, audio, video, or archives. Unlike encryption, which scrambles data so it is obvious something is protected, steganography tries to conceal the very existence of the hidden content. Attackers use it to tuck malware commands, payload fragments, or configuration data into files that appear harmless at first glance.
In cyber security, steganography matters because it can defeat simple filters that look only at file type or reputation. A phishing attachment may seem like an ordinary image while secretly carrying the next stage of a loader. Defenders look for mismatches in file structure, unusual metadata, unexpected decoding behavior, and network activity after media processing. Steganography is not always malicious, but in attacks it is often used to delay detection and move data through systems that trust common file formats.