Detection rules › Splunk
Windows MOVEit Transfer Writing ASPX
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.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | T1133 External Remote Services, T1190 Exploit Public-Facing Application |
| Persistence | T1133 External Remote Services |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 11 | FileCreate |
Rule body splunk
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
drilldown_searches:
- name: View the detection results for - "$dest$"
search: '%original_detection_search% | search dest = "$dest$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$dest$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | 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: 7d
latest_offset: "0"
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
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1505.003/moveit_windows-sysmon.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: XmlWinEventLog
test_type: unit
Stages and Predicates
Stage 1: tstats
| 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
Stage 2: search
| `drop_dm_object_name(Filesystem)`
Stage 3: search
| `security_content_ctime(firstTime)`
Stage 4: search
| `security_content_ctime(lastTime)`
Stage 5: search
| `windows_moveit_transfer_writing_aspx_filter`
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Filesystem.file_name | in |
|
Filesystem.file_path | in |
|