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Description

This search looks for system processes that typically execute from C:\Windows\System32\ or C:\Windows\SysWOW64. This may indicate a malicious process that is trying to hide as a legitimate process.
This detection utilizes a lookup that is deduped system32 and syswow64 directories from Server 2016 and Windows 10.
During triage, review the parallel processes - what process moved the native Windows binary? identify any artifacts on disk and review. If a remote destination is contacted, what is the reputation?

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint- Datasource: Splunk Add-on for Sysmon
  • Last Updated: 2020-12-08
  • Author: David Dorsey, Michael Haag, Splunk
  • ID: a34aae96-ccf8-4aef-952c-3ea21444444d

Annotations

ATT&CK
ID Technique Tactic
T1036 Masquerading Defense Evasion
T1036.003 Rename System Utilities Defense Evasion
Kill Chain Phase
  • Actions on Objectives
NIST
  • PR.PT
  • DE.CM
CIS20
  • CIS 8
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_path !="C:\\Windows\\System32*" Processes.process_path !="C:\\Windows\\SysWOW64*" by Processes.dest Processes.user Processes.parent_process Processes.process_name Processes.process Processes.process_id Processes.parent_process_id Processes.process_hash 
| `drop_dm_object_name("Processes")` 
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `is_windows_system_file` 
| `system_processes_run_from_unexpected_locations_filter`

Macros

The SPL above uses the following Macros:

Note that system_processes_run_from_unexpected_locations_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.process_path
  • Processes.user
  • Processes.dest
  • Processes.process_name
  • Processes.process_id
  • Processes.parent_process_name
  • Processes.process_hash

How To Implement

To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Processes node.

Known False Positives

This detection may require tuning based on third party applications utilizing native Windows binaries in non-standard paths.

Associated Analytic story

RBA

Risk Score Impact Confidence Message
49.0 70 70 System process running from unexpected location on $dest$

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

source | version: 6