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Description

The following analytic detects any system integrity level process spawned by a non-system account. It leverages Sysmon EventID 1, focusing on process integrity and parent user data. This behavior is significant as it often indicates successful privilege escalation to SYSTEM from a user-controlled process or service. If confirmed malicious, this activity could allow an attacker to gain full control over the system, execute arbitrary code, and potentially compromise the entire environment.

  • Type: TTP

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-05-28
  • Author: Steven Dick
  • ID: 5a5351cd-ba7e-499e-ad82-2ce160ffa637

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1068 Exploitation for Privilege Escalation Privilege Escalation
T1548 Abuse Elevation Control Mechanism Privilege Escalation, Defense Evasion
T1134 Access Token Manipulation Defense Evasion, Privilege Escalation
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


1
2
3
4
5
6



`sysmon` EventCode=1 IntegrityLevel="system" ParentUser=* NOT ParentUser IN ("*SYSTEM","*LOCAL SERVICE","*NETWORK SERVICE","*DWM-*","*$","-") 
| eval src_user = replace(ParentUser,"^[^\\\]+\\\\","") 
| stats count min(_time) as firstTime max(_time) as lastTime values(process_name) as process_name values(process) as process, values(process_path) as process_path, values(process_current_directory) as process_current_directory values(parent_process) as parent_process by dest, user, src_user, parent_process_name, parent_process_guid 
| `security_content_ctime(firstTime)`  
| `security_content_ctime(lastTime)` 
| `windows_privilege_escalation_system_process_without_system_parent_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_privilege_escalation_system_process_without_system_parent_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
  • dest
  • user
  • ParentUser
  • parent_process_name
  • parent_process_guid
  • IntegrityLevel

How To Implement

Target environment must ingest sysmon data, specifically Event ID 1 with process integrity and parent user data.

Known False Positives

Unknown

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
80.0 100 80 The process [$process_name$] on $dest$ was launched with system level integrity by $src_user$.

: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: 2