t1553-005-mark-of-the-web-bypass

name	T1553.005_mark-of-the-web-bypass
description	Adversaries may abuse specific file formats to subvert Mark-of-the-Web (MOTW) controls.
category	configuration
version	18.1
author	cyberstrike-official
tags	["mitre-attack","enterprise","t1553.005","defense-evasion","windows","sub-technique"]
technique_id	T1553.005
tactic	defense-evasion
all_tactics	["defense-evasion"]
platforms	["Windows"]
mitre_url	https://attack.mitre.org/techniques/T1553/005
tech_stack	["windows"]
cwe_ids	["CWE-693"]
chains_with	["T1553","T1553.001","T1553.002","T1553.003","T1553.004","T1553.006"]
prerequisites	["T1553"]
severity_boost	{"T1553":"Chain with T1553 for deeper attack path","T1553.001":"Chain with T1553.001 for deeper attack path","T1553.002":"Chain with T1553.002 for deeper attack path"}

T1553.005 Mark-of-the-Web Bypass

Sub-technique of: T1553

High-Level 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.

Kill Chain Phase

• Defense Evasion (TA0005)

Platforms: Windows

What to Check

• Identify if Mark-of-the-Web Bypass technique is applicable to target environment
• Check Windows systems for indicators of Mark-of-the-Web Bypass
• Verify mitigations are bypassed or absent (2 known mitigations)
• Assess detection coverage (1 detection strategies)

How to Test

Atomic Red Team Tests

The following tests are from Atomic Red Team and provide actionable ways to test this technique:

Atomic Test 1: Mount ISO image

Mounts ISO image downloaded from internet to evade Mark-of-the-Web. Upon successful execution, powershell will download the .iso from the Atomic Red Team repo, and mount the image. The provided sample ISO simply has a Reports shortcut file in it. Reference: https://www.microsoft.com/security/blog/2021/05/27/new-sophisticated-email-based-attack-from-nobelium/