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Description

This search is to detect a suspicious whoami execution to check if the cmd or shell instance process is with elevated privileges. This technique was seen in FIN7 js implant where it execute this as part of its data collection to the infected machine to check if the running shell cmd process is elevated or not. This TTP is really a good alert for known attacker that recon on the targetted host. This command is not so commonly executed by a normal user or even an admin to check if a process is elevated.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint- Datasource: Splunk Add-on for Sysmon
  • Last Updated: 2021-09-15
  • Author: Teoderick Contreras, Splunk
  • ID: a9079b18-1633-11ec-859c-acde48001122

Annotations

ATT&CK
ID Technique Tactic
T1033 System Owner/User Discovery Discovery
Kill Chain Phase
  • Exploitation
NIST
CIS20
CVE
1
2
3
4
5
6
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where  Processes.process = "*whoami*" Processes.process = "*/group*" Processes.process = "* find *" Processes.process = "*12288*" by Processes.dest Processes.user Processes.parent_process Processes.process_name Processes.process Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `check_elevated_cmd_using_whoami_filter`

Macros

The SPL above uses the following Macros:

Note that check_elevated_cmd_using_whoami_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required field

  • _time
  • Processes.parent_process_name
  • Processes.parent_process
  • Processes.process_name
  • Processes.process_id
  • Processes.process
  • Processes.dest
  • Processes.user

How To Implement

To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA. Tune and filter known instances where renamed rundll32.exe may be used.

Known False Positives

unknown

Associated Analytic story

RBA

Risk Score Impact Confidence Message
56.0 70 80 Process name $process_name$ with commandline $process$ in $dest$

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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