An attacker exploits the functionality of Microsoft NTFS Alternate Data Streams (ADS) to undermine system security. ADS allows multiple "files" to be stored in one directory entry referenced as filename:streamname. One or more alternate data streams may be stored in any file or directory. Normal Microsoft utilities do not show the presence of an ADS stream attached to a file. The additional space for the ADS is not recorded in the displayed file size. The additional space for ADS is accounted for in the used space on the volume. An ADS can be any type of file. ADS are copied by standard Microsoft utilities between NTFS volumes. ADS can be used by an attacker or intruder to hide tools, scripts, and data from detection by normal system utilities. Many anti-virus programs do not check for or scan ADS. Windows Vista does have a switch (-R) on the command line DIR command that will display alternate streams.
This table shows the other attack patterns and high level categories that are related to this attack pattern. These relationships are defined as ChildOf and ParentOf, and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as CanFollow, PeerOf, and CanAlsoBe are defined to show similar attack patterns that the user may want to explore.
Standard Attack Pattern - A standard level attack pattern in CAPEC is focused on a specific methodology or technique used in an attack. It is often seen as a singular piece of a fully executed attack. A standard attack pattern is meant to provide sufficient details to understand the specific technique and how it attempts to accomplish a desired goal. A standard level attack pattern is a specific type of a more abstract meta level attack pattern.
The target must be running the Microsoft NTFS file system.
The attacker must have command line or programmatic access to the target's files system with write/read permissions.
Design: Use FAT file systems which do not support Alternate Data Streams.
Implementation: Use Vista dir with the -R switch or utility to find Alternate Data Streams and take appropriate action with those discovered.
Implementation: Use products that are Alternate Data Stream aware for virus scanning and system security operations.
A Related Weakness relationship associates a weakness with this attack pattern. Each association implies a weakness that must exist for a given attack to be successful. If multiple weaknesses are associated with the attack pattern, then any of the weaknesses (but not necessarily all) may be present for the attack to be successful. Each related weakness is identified by a CWE identifier.