Stego (from Steganography) is a technique for hiding information in a picture, such as a BMP or JPEG, or in a music file. Stego works by replacing bits of useless or unused data in regular computer files (such as graphics, sound, text, HTML, etc.) with bits of different, invisible information. This hidden information can be plain text, cipher text, or even images. Stego sometimes is used when encryption is not permitted. Or, more commonly, Stego is used to supplement encryption. An encrypted file may still hide information using steganography, so even if the encrypted file is deciphered, the hidden message is not visible. Although Stego is not commonly used to hide Spyware, it is possible to hide files within an image and then install the Spyware on the user's system when the user opens the image. If such hidden files are polymorphic or metamorphic, they are extremely difficult to detect and remove. |