Steganography is a term that describes the practice of hiding secret text messages and other content inside non-secret messages. At least three major cyberespionage campaigns in the past few months have used steganography to hide stolen data and to communicate with command and control servers. In these campaigns, threat actors have exfiltrated data from victim organizations by hiding it inside the code of seemingly ordinary image or video files and sending it to C&C servers. The modifications to the images or videos are so minute that they usually have gone unnoticed and typical endpoint antimalware tools are not designed to look for or spot data exfiltration.”]