Windows MOVEit Transfer Writing ASPX

name: Windows MOVEit Transfer Writing ASPX
id: c0ed2aca-5666-45b3-813f-ddfac3f3eda0
version: 12
creation_date: '2023-06-01'
modification_date: '2026-05-13'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following analytic detects the creation of new ASPX files in the MOVEit Transfer application's "wwwroot" directory. It leverages endpoint data on process and filesystem activity to identify processes responsible for creating these files. This activity is significant as it may indicate exploitation of a critical zero-day vulnerability in MOVEit Transfer, used by threat actors to install malicious ASPX files. If confirmed malicious, this could lead to exfiltration of sensitive data, including user credentials and file metadata, posing a severe risk to the organization's security.
data_source:
    - Sysmon EventID 11
search: |
    | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
    as lastTime FROM datamodel=Endpoint.Filesystem where
      Filesystem.file_path IN ("*\\MOVEitTransfer\\wwwroot\\*") AND
      Filesystem.file_name IN("*.ashx", "*.asp*")
    by Filesystem.action Filesystem.dest Filesystem.file_access_time Filesystem.file_create_time
    Filesystem.file_hash Filesystem.file_modify_time Filesystem.file_name Filesystem.file_path
    Filesystem.file_acl Filesystem.file_size Filesystem.process_guid Filesystem.process_id
    Filesystem.user Filesystem.vendor_product
    | `drop_dm_object_name(Filesystem)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_moveit_transfer_writing_aspx_filter`
how_to_implement: |
    To successfully implement this search you need to be ingesting information
    on process that include the name of the process responsible for the changes from
    your endpoints into the `Endpoint` datamodel in the `Processes` node and `Filesystem`
    node.
known_false_positives: |
    The query is structured in a way that `action` (read, create)
    is not defined. Review the results of this query, filter, and tune as necessary.
    It may be necessary to generate this query specific to your endpoint product.
references:
    - https://community.progress.com/s/article/MOVEit-Transfer-Critical-Vulnerability-31May2023
    - https://www.reddit.com/r/sysadmin/comments/13wxuej/critical_vulnerability_moveit_file_transfer/
    - https://www.bleepingcomputer.com/news/security/new-moveit-transfer-zero-day-mass-exploited-in-data-theft-attacks/
    - https://www.reddit.com/r/sysadmin/comments/13wxuej/critical_vulnerability_moveit_file_transfer/
    - https://www.mandiant.com/resources/blog/zero-day-moveit-data-theft
finding:
    title: The MOVEit application on $dest$ has written a new ASPX file $file_name$ to disk.
    entity:
        field: dest
        type: system
        score: 50
threat_objects:
    - field: file_name
      type: file_name
analytic_story:
    - MOVEit Transfer Critical Vulnerability
    - Hellcat Ransomware
asset_type: Endpoint
mitre_attack_id:
    - T1190
    - T1133
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint