Detection rules › Splunk

Windows Hunting System Account Targeting Lsass

Status
production
Group by
CallTrace, GrantedAccess, Guid, Opcode, SecurityID, SourceProcessGUID, TargetProcessGUID, TargetProcessId, dest, parent_process_guid, parent_process_id, parent_process_name, process_guid, process_id, process_name, signature, signature_id, target_process_name, user, user_id, vendor_product
Author
Michael Haag, Splunk
Source
github.com/splunk/security_content

The following analytic identifies processes attempting to access Lsass.exe, which may indicate credential dumping or applications needing credential access. It leverages Sysmon EventCode 10 to detect such activities by analyzing fields like TargetImage, GrantedAccess, and SourceImage. This behavior is significant as unauthorized access to Lsass.exe can lead to credential theft, posing a severe security risk. If confirmed malicious, attackers could gain access to sensitive credentials, potentially leading to privilege escalation and further compromise of the environment.

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1003.001 OS Credential Dumping: LSASS Memory

Event coverage

ProviderEventTitle
SysmonEvent ID 10ProcessAccess

Rule body splunk

name: Windows Hunting System Account Targeting Lsass
id: 1c6abb08-73d1-11ec-9ca0-acde48001122
version: 12
creation_date: '2022-01-11'
modification_date: '2026-05-13'
author: Michael Haag, Splunk
status: production
type: Hunting
description: The following analytic identifies processes attempting to access Lsass.exe, which may indicate credential dumping or applications needing credential access. It leverages Sysmon EventCode 10 to detect such activities by analyzing fields like TargetImage, GrantedAccess, and SourceImage. This behavior is significant as unauthorized access to Lsass.exe can lead to credential theft, posing a severe security risk. If confirmed malicious, attackers could gain access to sensitive credentials, potentially leading to privilege escalation and further compromise of the environment.
data_source:
    - Sysmon EventID 10
search: |-
    `sysmon` EventCode=10 TargetImage=*lsass.exe
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY CallTrace EventID GrantedAccess
           Guid Opcode ProcessID
           SecurityID SourceImage SourceProcessGUID
           SourceProcessId TargetImage TargetProcessGUID
           TargetProcessId UserID dest
           granted_access parent_process_exec parent_process_guid
           parent_process_id parent_process_name parent_process_path
           process_exec process_guid process_id
           process_name process_path signature
           signature_id user_id vendor_product
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `windows_hunting_system_account_targeting_lsass_filter`
how_to_implement: To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA. Enabling EventCode 10 TargetProcess lsass.exe is required.
known_false_positives: False positives will occur based on GrantedAccess and SourceUser, filter based on source image as needed. Utilize this hunting analytic to tune out false positives in TTP or anomaly analytics.
references:
    - https://en.wikipedia.org/wiki/Local_Security_Authority_Subsystem_Service
    - https://docs.microsoft.com/en-us/windows/win32/api/minidumpapiset/nf-minidumpapiset-minidumpwritedump
    - https://cyberwardog.blogspot.com/2017/03/chronicles-of-threat-hunter-hunting-for_22.html
    - https://raw.githubusercontent.com/PowerShellMafia/PowerSploit/master/Exfiltration/Invoke-Mimikatz.ps1
    - https://docs.microsoft.com/en-us/windows/win32/procthread/process-security-and-access-rights?redirectedfrom=MSDN
analytic_story:
    - CISA AA23-347A
    - Credential Dumping
    - Lokibot
    - Scattered Lapsus$ Hunters
asset_type: Endpoint
mitre_attack_id:
    - T1003.001
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1003.001/atomic_red_team/windows-sysmon_creddump.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

Stages and Predicates

Stage 1: search

`sysmon` EventCode=10 TargetImage=*lsass.exe

Stage 2: stats

| stats count min(_time) as firstTime max(_time) as lastTime
    BY CallTrace EventID GrantedAccess
       Guid Opcode ProcessID
       SecurityID SourceImage SourceProcessGUID
       SourceProcessId TargetImage TargetProcessGUID
       TargetProcessId UserID dest
       granted_access parent_process_exec parent_process_guid
       parent_process_id parent_process_name parent_process_path
       process_exec process_guid process_id
       process_name process_path signature
       signature_id user_id vendor_product

Stage 3: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `security_content_ctime(lastTime)`

Stage 5: search

| `windows_hunting_system_account_targeting_lsass_filter`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
EventCodeeq
  • 10 corpus 16 (splunk 15, kusto 1)
TargetImageeq
  • *lsass.exe corpus 6 (splunk 6)