North Korea embeds hidden metadata watermarks in operating system files to trace digital documents to original computers

North Korea's state-developed Red Star OS embeds metadata watermarks into files, allowing authorities to identify and trace digital documents back to the computer that created them, according to the investigation. The country operates a heavily restricted digital ecosystem including state-controlled smartphones and an isolated intranet called Kwangmyong filled with propaganda, with surveillance software reportedly capturing screenshots of user activity. The source characterizes these systems as built explicitly for surveillance and regime control over the population's access to information and technology.