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Description

The following analytic identifies a suspicious msdtc.exe with specific command-line parameters, particularly -a or -b, which are regarded as potential indicators of the presence of the insidious PlugX malware. This malware is notorious for its covert operations and is frequently utilized by threat actors for unauthorized access, data exfiltration, and espionage. The analytic's focus on the -a or -b command-line parameters within msdtc.exe is rooted in the PlugX malware's sophisticated tactic of masquerading its activities. To elude detection, PlugX employs a technique where it injects a concealed, headless PlugX Dynamic Link Library (DLL) module into the legitimate msdtc.exe process. By leveraging these specific command-line parameters, the malware attempts to disguise its presence within a system's legitimate processes, thereby evading immediate suspicion.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2023-11-21
  • Author: Teoderick Contreras, Splunk
  • ID: 238f3a07-8440-480b-b26f-462f41d9a47c

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1036 Masquerading Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


1
2
3
4
5
6



| tstats `security_content_summariesonly` min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name = "msdtc.exe" Processes.process = "*msdtc.exe*" Processes.process IN ("* -a*", "* -b*") by Processes.dest Processes.user Processes.parent_process_name Processes.parent_process Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_masquerading_msdtc_process_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_masquerading_msdtc_process_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Processes.dest
  • Processes.user
  • Processes.parent_process_name
  • Processes.parent_process
  • Processes.original_file_name
  • Processes.process_name
  • Processes.process
  • Processes.process_id
  • Processes.parent_process_path
  • Processes.process_path
  • Processes.parent_process_id

How To Implement

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

unknown

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
64.0 80 80 msdtc.exe process with process commandline used by PlugX malware in $dest$.

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

Reference

Test Dataset

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

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