Detection: Access LSASS Memory for Dump Creation

Updated Date: 2025-02-10 ID: fb4c31b0-13e8-4155-8aa5-24de4b8d6717 Author: Patrick Bareiss, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects attempts to dump the LSASS process memory, a common technique in credential dumping attacks. It leverages Sysmon logs, specifically EventCode 10, to identify suspicious call traces to dbgcore.dll and dbghelp.dll associated with lsass.exe. This activity is significant as it often precedes the theft of sensitive login credentials, posing a high risk of unauthorized access to systems and data. If confirmed malicious, attackers could gain access to critical credentials, enabling further compromise and lateral movement within the network.

1`sysmon` EventCode=10 TargetImage=*lsass.exe CallTrace=*dbgcore.dll* OR CallTrace=*dbghelp.dll* 
2| 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 
3| `security_content_ctime(firstTime)` 
4|`security_content_ctime(lastTime)` 
5| `access_lsass_memory_for_dump_creation_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($field$)
access_lsass_memory_for_dump_creation_filter search *
access_lsass_memory_for_dump_creation_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
Exploitation
DE.CM
CIS 10

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
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

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

Administrators can create memory dumps for debugging purposes, but memory dumps of the LSASS process would be unusual.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

process $SourceImage$ injected into $TargetImage$ and was attempted dump LSASS on $dest$. Adversaries tend to do this when trying to accesss credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).

Risk Object Risk Object Type Risk Score Threat Objects
dest system 63 TargetImage

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: 8