ID | Technique | Tactic |
---|---|---|
T1003.001 | LSASS Memory | Credential Access |
T1003 | OS Credential Dumping | Credential Access |
Detection: Windows Non-System Account Targeting Lsass
Description
The following analytic identifies non-SYSTEM accounts requesting access to lsass.exe. This detection leverages Sysmon EventCode 10 logs to monitor access attempts to the Local Security Authority Subsystem Service (lsass.exe) by non-SYSTEM users. This activity is significant as it may indicate credential dumping attempts or unauthorized access to sensitive credentials. If confirmed malicious, an attacker could potentially extract credentials from memory, leading to privilege escalation or lateral movement within the network. Immediate investigation is required to determine the legitimacy of the access request and to mitigate any potential threats.
Search
1`sysmon` EventCode=10 TargetImage=*lsass.exe NOT (SourceUser="NT AUTHORITY\\*")
2| stats count min(_time) as firstTime max(_time) as lastTime by dest, parent_process_name, parent_process_path ,parent_process_id, TargetImage, GrantedAccess, SourceUser, TargetUser
3| rename TargetUser as user
4| `security_content_ctime(firstTime)`
5| `security_content_ctime(lastTime)`
6| `windows_non_system_account_targeting_lsass_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
Sysmon EventID 10 | Windows | 'xmlwineventlog' |
'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational' |
N/A |
Macros Used
Name | Value |
---|---|
security_content_ctime | convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$) |
windows_non_system_account_targeting_lsass_filter | search * |
windows_non_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
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 Notable | Yes |
Rule Title | %name% |
Rule Description | %description% |
Notable Event Fields | user, dest |
Creates Risk Event | True |
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 legitimate application requests, filter based on source image as needed.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
A process, $parent_process_path$, has loaded $TargetImage$ that are typically related to credential dumping on $dest$. Review for further details. | 64 | 80 | 80 |
References
-
https://en.wikipedia.org/wiki/Local_Security_Authority_Subsystem_Service
-
https://cyberwardog.blogspot.com/2017/03/chronicles-of-threat-hunter-hunting-for_22.html
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