Detection: Loading Of Dynwrapx Module

Updated Date: 2024-05-26 ID: eac5e8ba-4857-11ec-9371-acde48001122 Author: Teoderick Contreras, Splunk Type: TTP Product: Splunk Enterprise Security

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.

Search

1`sysmon` EventCode=7 (ImageLoaded = "*\\dynwrapx.dll" OR OriginalFileName = "dynwrapx.dll" OR  Product = "DynamicWrapperX") 
2| stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded OriginalFileName Product process_name dest EventCode Signed ProcessId 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `loading_of_dynwrapx_module_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
Sysmon EventID 7	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`	N/A

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
loading_of_dynwrapx_module_filter	`search *`

loading_of_dynwrapx_module_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1055	Process Injection	Defense Evasion
T1055.001	Dynamic-link Library Injection	Privilege Escalation

KillChainPhase.EXPLOITAITON

NistCategory.DE_CM

Cis18Value.CIS_10

APT32

APT37

APT41

APT5

Cobalt Group

Kimsuky

PLATINUM

Silence

TA2541

Turla

Wizard Spider

BackdoorDiplomacy

Lazarus Group

Leviathan

Malteiro

Putter Panda

TA505

Tropic Trooper

Turla

Wizard Spider

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Notable	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Risk Event	True

This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

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).

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
dynwrapx.dll loaded by process $process_name$ on $dest$	80	80	100

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`xmlwineventlog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`xmlwineventlog`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 2