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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: Anomaly
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2020-12-08
  • Author: David Dorsey, Michael Haag, Splunk
  • ID: a34aae96-ccf8-4aef-952c-3ea21444444d

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1036 Masquerading Defense Evasion
T1036.003 Rename System Utilities Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE
1
2
3
4
5
6
7
| 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_path 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:

:information_source: 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 fields

List of fields required to use this analytic.

  • _time
  • Processes.process_path
  • Processes.user
  • Processes.dest
  • Processes.process_name
  • Processes.process_id
  • Processes.parent_process_name
  • Processes.process_hash

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

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
30.0 60 50 A System process $process_name$ is running from $process_path$ on $dest$, potentially non-standard.

: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

source | version: 6