Detection: System Processes Run From Unexpected Locations

Description

The following analytic identifies system processes running from unexpected locations outside C:\Windows\System32\ or C:\Windows\SysWOW64. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process paths, names, and hashes. This activity is significant as it may indicate a malicious process attempting to masquerade as a legitimate system process. If confirmed malicious, this behavior could allow an attacker to execute code, escalate privileges, or maintain persistence within the environment, posing a significant security risk.

Search

1
2| 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 
3| `drop_dm_object_name("Processes")` 
4| `security_content_ctime(firstTime)`
5| `security_content_ctime(lastTime)`
6| `is_windows_system_file_macro` 
7| `system_processes_run_from_unexpected_locations_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	N/A	'crowdstrike:events:sensor'	'crowdstrike'
Sysmon EventID 1	Windows	'xmlwineventlog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Windows Event Log Security 4688	Windows	'xmlwineventlog'	'XmlWinEventLog:Security'

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

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

• DarkGate Malware

• Masquerading - Rename System Utilities

• Qakbot

• Ransomware

• Suspicious Command-Line Executions

• Unusual Processes

• Windows Error Reporting Service Elevation of Privilege Vulnerability

Risk Based Analytics (RBA)

References

• https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1036.003/T1036.003.yaml

• https://attack.mitre.org/techniques/T1036/003/

Detection Testing

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: GitHub | Version: 8