T1553.005 — Subvert Trust Controls: Mark-of-the-Web Bypass
Sub-technique of T1553 Subvert Trust Controls
Description
Adversaries may abuse specific file formats to subvert Mark-of-the-Web (MOTW) controls. In Windows, when files are downloaded from the Internet, they are tagged with a hidden NTFS Alternate Data Stream (ADS) named Zone.Identifier with a specific value known as the MOTW. Files that are tagged with MOTW are protected and cannot perform certain actions. For example, starting in MS Office 10, if a MS Office file has the MOTW, it will open in Protected View. Executables tagged with the MOTW will be processed by Windows Defender SmartScreen that compares files with an allowlist of well-known executables. If the file is not known/trusted, SmartScreen will prevent the execution and warn the user not to run it.
Adversaries may abuse container files such as compressed/archive (.arj, .gzip) and/or disk image (.iso, .vhd) file formats to deliver malicious payloads that may not be tagged with MOTW. Container files downloaded from the Internet will be marked with MOTW but the files within may not inherit the MOTW after the container files are extracted and/or mounted. MOTW is a NTFS feature and many container files do not support NTFS alternative data streams. After a container file is extracted and/or mounted, the files contained within them may be treated as local files on disk and run without protections.
Detected by EasySIEM
This project's own SigmaHQ-derived detection pipeline tags every compiled rule with the ATT&CK technique(s) it maps to -- if a rule in your install covers this technique, it shows up automatically on your own Grafana Alerts dashboard's "Top ATT&CK Techniques" panel, no lookup needed. This page exists so a click from there always lands here on easysiem.com, not on attack.mitre.org.