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Description

The following analytic identifies a suspicious process command line fetching the environment variables with a non-shell parent process. This technique was seen in qakbot malware where it fetches the environment variable in the target or compromised host. This TTP detection is a good pivot of possible malicious behavior since the command line is executed by a common non-shell process like cmd.exe , powershell.exe and many more. This can also be a good sign that the parent process has a malicious code injected to it to execute this command.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2022-10-27
  • Author: Teoderick Contreras, Splunk
  • ID: 048839e4-1eaa-43ff-8a22-86d17f6fcc13

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1055 Process Injection Defense Evasion, Privilege Escalation
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process = "*cmd /c set" OR Processes.process = "*cmd.exe /c set" AND NOT (Processes.parent_process_name = "cmd.exe" OR Processes.parent_process_name = "powershell*" OR Processes.parent_process_name="pwsh.exe" OR Processes.parent_process_name = "explorer.exe") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id Processes.original_file_name 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_command_shell_fetch_env_variables_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_command_shell_fetch_env_variables_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

shell process that are not included in this search may cause False positive. Filter is needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
56.0 80 70 non-shell parent process has a child process $process_name$ with a commandline $process$ to fetch env variables 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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