Detection: Windows Hunting System Account Targeting Lsass

Updated Date: 2024-10-17 ID: 1c6abb08-73d1-11ec-9ca0-acde48001122 Author: Michael Haag, Splunk Type: Hunting Product: Splunk Enterprise Security

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.

1`sysmon` EventCode=10 TargetImage=*lsass.exe 
2| stats count min(_time) as firstTime max(_time) as lastTime by dest, TargetImage, GrantedAccess, SourceImage, SourceProcessId, SourceUser, TargetUser  
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `windows_hunting_system_account_targeting_lsass_filter`

Data Source

Name Platform Sourcetype Source
Sysmon EventID 10 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
windows_hunting_system_account_targeting_lsass_filter search *
windows_hunting_system_account_targeting_lsass_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1003.001 LSASS Memory Credential Access
T1003 OS Credential Dumping Credential Access
KillChainPhase.EXPLOITAITON
NistCategory.DE_AE
Cis18Value.CIS_10
APT1
APT28
APT3
APT32
APT33
APT39
APT41
APT5
Agrius
Aquatic Panda
BRONZE BUTLER
Blue Mockingbird
Cleaver
Earth Lusca
Ember Bear
FIN13
FIN6
FIN8
Fox Kitten
GALLIUM
HAFNIUM
Indrik Spider
Ke3chang
Kimsuky
Leafminer
Leviathan
Magic Hound
Moonstone Sleet
MuddyWater
OilRig
PLATINUM
Play
RedCurl
Sandworm Team
Silence
Threat Group-3390
Volt Typhoon
Whitefly
Wizard Spider
APT28
APT32
APT39
Axiom
Ember Bear
Leviathan
Poseidon Group
Sowbug
Suckfly
Tonto Team

Default Configuration

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

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Risk Event False
This configuration file applies to all detections of type hunting.

Implementation

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.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
A process, $SourceImage$, has requested access to LSASS on $dest$. Review for further details. 64 80 80
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog
Integration ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog

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: 4