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Description

The following analytic detects a suspicious process attempting to terminate the Lsass.exe process. It leverages Sysmon EventCode 10 logs to identify processes granted PROCESS_TERMINATE access to Lsass.exe. This activity is significant because Lsass.exe is a critical process responsible for enforcing security policies and handling user credentials. If confirmed malicious, this behavior could indicate an attempt to perform credential dumping, privilege escalation, or evasion of security policies, potentially leading to unauthorized access and persistence within the environment.

  • Type: Anomaly

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

  • Last Updated: 2024-05-23
  • Author: Teoderick Contreras, Splunk
  • ID: 7ab3c319-a4e7-4211-9e8c-40a049d0dba6

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1562.001 Disable or Modify Tools Defense Evasion
T1562 Impair Defenses Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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`sysmon` EventCode=10 TargetImage=*lsass.exe GrantedAccess = 0x1 
| stats count min(_time) as firstTime max(_time) as lastTime by SourceImage, TargetImage, TargetProcessId, SourceProcessId, GrantedAccess CallTrace, dest 
| rename dest as dest 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_terminating_lsass_process_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_terminating_lsass_process_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
  • EventCode
  • TargetImage
  • CallTrace
  • dest
  • TargetProcessId
  • SourceImage
  • SourceProcessId
  • GrantedAccess

How To Implement

This search requires Sysmon Logs and a Sysmon configuration, which includes EventCode 10 for lsass.exe. This search uses an input macro named sysmon. We strongly recommend that you specify your environment-specific configurations (index, source, sourcetype, etc.) for Windows Sysmon logs. Replace the macro definition with configurations for your Splunk environment. The search also uses a post-filter macro designed to filter out known false positives.

Known False Positives

unknown

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
64.0 80 80 a process $SourceImage$ terminates Lsass process in $dest$

: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