splunk_escuTTP

Windows Mark Of The Web Bypass

The following analytic identifies a suspicious process that deletes the Mark-of-the-Web (MOTW) data stream. It leverages Sysmon EventCode 23 to detect when a file's Zone.Identifier stream is removed. This activity is significant because it is a common technique used by malware, such as Ave Maria RAT, to bypass security restrictions on files downloaded from the internet. If confirmed malicious, this behavior could allow an attacker to execute potentially harmful files without triggering security warnings, leading to further compromise of the system.

MITRE ATT&CK

T1553.005

Detection Query

`sysmon` EventCode=23 TargetFilename = "*:Zone.Identifier"
  | stats count min(_time) as firstTime, max(_time) as lastTime
    BY action dest dvc
       file_path file_hash file_name
       file_modify_time process_exec process_guid
       process_id process_name process_path
       signature signature_id user
       user_id vendor_product
  | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)`
  | `windows_mark_of_the_web_bypass_filter`

Author

Teoderick Contreras, Splunk

Created

2026-03-10

Data Sources

Sysmon EventID 23

References

Tags

Quasar RATWarzone RAT

Raw Content

name: Windows Mark Of The Web Bypass
id: 8ca13343-7405-4916-a2d1-ae34ce0c28ae
version: 10
date: '2026-03-10'
author: Teoderick Contreras, Splunk
status: production
type: TTP
data_source:
    - Sysmon EventID 23
description: The following analytic identifies a suspicious process that deletes the Mark-of-the-Web (MOTW) data stream. It leverages Sysmon EventCode 23 to detect when a file's Zone.Identifier stream is removed. This activity is significant because it is a common technique used by malware, such as Ave Maria RAT, to bypass security restrictions on files downloaded from the internet. If confirmed malicious, this behavior could allow an attacker to execute potentially harmful files without triggering security warnings, leading to further compromise of the system.
search: |-
    `sysmon` EventCode=23 TargetFilename = "*:Zone.Identifier"
      | stats count min(_time) as firstTime, max(_time) as lastTime
        BY action dest dvc
           file_path file_hash file_name
           file_modify_time process_exec process_guid
           process_id process_name process_path
           signature signature_id user
           user_id vendor_product
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `windows_mark_of_the_web_bypass_filter`
how_to_implement: To successfully implement this search, you need to be ingesting logs with the deleted target file name, process name and process id  from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.
known_false_positives: No false positives have been identified at this time.
references:
    - https://attack.mitre.org/techniques/T1553/005/
    - https://github.com/nmantani/PS-MOTW#remove-motwps1
drilldown_searches:
    - name: View the detection results for - "$user$" and "$dest$"
      search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") starthoursago=168  | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
rba:
    message: A mark-of-the-web data stream is deleted on $dest$
    risk_objects:
        - field: user
          type: user
          score: 50
        - field: dest
          type: system
          score: 50
    threat_objects: []
tags:
    analytic_story:
        - Quasar RAT
        - Warzone RAT
    asset_type: Endpoint
    mitre_attack_id:
        - T1553.005
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1553.005/mark_of_the_web_bypass/possible-motw-deletion.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog