Microsoft decided that they are too sensitive for ADS to handle. But the use of ADS for other purposes did not stop. Service Pack 2 for Windows XP introduced the Attachment Execution Service that stores details on the origin of downloaded files in an ADS called zone identifier, in an effort to protect users from downloaded files that may present a risk. Internet Explorer and Windows 8 extended this function through SmartScreen. Internet Explorer also uses ADS to store favicons in Internet shortcut files. Sun Solaris version 9 and later allows files to have forks. Forks are called extended attributes in Solaris, although they are not within the usual meaning of "extended attribute". The maximum size of a Solaris-type extended attribute is the same as the maximum size of a file, and they are read and written in the same fashion as files. Internally, they are actually stored and accessed like normal files, so their ownership and permissions can differ from those of the parent file. Sub-directories are administratively disabled, so their names cannot contain "/" characters. Extended attributes in Network File System Version 4 are similar to Solaris-style extended attributes. Possible security and data loss risks When a file system supports different forks, the applications should be aware of them, or security risks can arise. Allowing legacy software to access data without appropriate shims in place is the primary culprit for such problems. If the different system utilities (disk explorer, antivirus software, archivers, and so on), are not aware of the different forks, the following problems can arise: The user will never know the presence of any alternate fork nor the total size of the file, just of the main data fork. Computer viruses can hide in alternate forks on Windows and never get detected if the antivirus software is not aware of forks. Data can be lost when sending files via fork-unaware channels, such as e-mail, file systems without support for forks, or even when copying files between file systems with forks support if the program that made the copy does not support forks or when compressing files with software that does not support forks. References External links MSDN Library: File Streams Alternate Data Streams Alternate Data Streams in Windows NTFS Alternate Streams Computer file systems