Detection rules › Splunk
Loading Of Dynwrapx Module
The following analytic detects the loading of the dynwrapx.dll module, which is associated with the DynamicWrapperX ActiveX component. This detection leverages Sysmon EventCode 7 to identify processes that load or register dynwrapx.dll. This activity is significant because DynamicWrapperX can be used to call Windows API functions in scripts, making it a potential tool for malicious actions. If confirmed malicious, this could allow an attacker to execute arbitrary code, escalate privileges, or maintain persistence on the host. Immediate investigation of parallel processes and registry modifications is recommended.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Privilege Escalation | T1055.001 Process Injection: Dynamic-link Library Injection |
| Stealth | T1055.001 Process Injection: Dynamic-link Library Injection |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 7 | Image loaded |
Rule body splunk
name: Loading Of Dynwrapx Module
id: eac5e8ba-4857-11ec-9371-acde48001122
version: 10
creation_date: '2021-10-05'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: The following analytic detects the loading of the dynwrapx.dll module, which is associated with the DynamicWrapperX ActiveX component. This detection leverages Sysmon EventCode 7 to identify processes that load or register dynwrapx.dll. This activity is significant because DynamicWrapperX can be used to call Windows API functions in scripts, making it a potential tool for malicious actions. If confirmed malicious, this could allow an attacker to execute arbitrary code, escalate privileges, or maintain persistence on the host. Immediate investigation of parallel processes and registry modifications is recommended.
data_source:
- Sysmon EventID 7
search: '`sysmon` EventCode=7 (ImageLoaded = "*\\dynwrapx.dll" OR OriginalFileName = "dynwrapx.dll" OR Product = "DynamicWrapperX") | fillnull | stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded dest loaded_file loaded_file_path original_file_name process_exec process_guid process_hash process_id process_name process_path service_dll_signature_exists service_dll_signature_verified signature signature_id user_id vendor_product | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `loading_of_dynwrapx_module_filter`'
how_to_implement: To successfully implement this search you need to be ingesting information on processes that include the name of the process responsible for the changes from your endpoints into the `Endpoint` datamodel in the `Processes` and `Filesystem` node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.
known_false_positives: False positives should be limited, however it is possible to filter by Processes.process_name and specific processes (ex. wscript.exe). Filter as needed. This may need modification based on EDR telemetry and how it brings in registry data. For example, removal of (Default).
references:
- https://blog.f-secure.com/hunting-for-koadic-a-com-based-rootkit/
- https://www.script-coding.com/dynwrapx_eng.html
- https://bohops.com/2018/06/28/abusing-com-registry-structure-clsid-localserver32-inprocserver32/
- https://tria.ge/210929-ap75vsddan
- https://www.virustotal.com/gui/file/cb77b93150cb0f7fe65ce8a7e2a5781e727419451355a7736db84109fa215a89
- https://malpedia.caad.fkie.fraunhofer.de/details/win.asyncrat
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: dynwrapx.dll loaded by process $process_name$ on $dest$
entity:
field: dest
type: system
score: 50
analytic_story:
- Remcos
- AsyncRAT
asset_type: Endpoint
mitre_attack_id:
- T1055.001
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/malware/remcos/remcos_dynwrapx/sysmon_dynwraper.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: XmlWinEventLog
test_type: unit
Stages and Predicates
Stage 1: search
`sysmon` EventCode=7 (ImageLoaded = "*\\dynwrapx.dll" OR OriginalFileName = "dynwrapx.dll" OR Product = "DynamicWrapperX")
Stage 2: fillnull
| fillnull
Stage 3: stats
| stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded dest loaded_file loaded_file_path original_file_name process_exec process_guid process_hash process_id process_name process_path service_dll_signature_exists service_dll_signature_verified signature signature_id user_id vendor_product
Stage 4: search
| `security_content_ctime(firstTime)`
Stage 5: search
| `security_content_ctime(lastTime)`
Stage 6: search
| `loading_of_dynwrapx_module_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 |
|---|---|---|
EventCode | eq |
|
ImageLoaded | eq |
|
OriginalFileName | eq |
|
Product | eq |
|