ADS spy tool (also known as Alternative Data Streams spy tool) is a software application that helps in the detection and analysis of alternative data streams (ADS) on Windows operating systems. ADS refers to a feature of the NTFS file system that allows additional data to be associated with a file without changing its size or visible content. These data streams are not typically visible to users or ordinary file management tools. The purpose of an ADS spy tool is to identify hidden or malicious data streams that may be present on a system. Malware authors sometimes use ADS to hide their malicious code or files, making it difficult for traditional antivirus or anti-malware software to detect them. ADS spy tools can help security professionals and system administrators identify and investigate such hidden streams.