There are several ways to hide evidence of an attack, including hiding the files placed on the system such as executable files, scripts, and other data. Operating systems such as Windows provide many methods you can use to hide files, including file attributes and alternate data streams (ADS).
File attributes are a feature of operating systems that allow files to be marked as having certain properties, including read-only and hidden. Files can be flagged as hidden, which is a convenient way to hide data and prevent detection through simple means such as directory listings or browsing in Windows Explorer. Hiding files this way does not provide complete protection, however, because more advanced detection techniques can uncover files hidden in this manner.