Detection: Windows Possible Credential Dumping

Description

The following analytic detects potential credential dumping by identifying specific GrantedAccess permission requests and CallTrace DLLs targeting the LSASS process. It leverages Sysmon EventCode 10 logs, focusing on access requests to lsass.exe and call traces involving debug and native API DLLs like dbgcore.dll, dbghelp.dll, and ntdll.dll. This activity is significant as credential dumping can lead to unauthorized access to sensitive credentials. If confirmed malicious, attackers could gain elevated privileges and persist within the environment, posing a severe security risk.

1`sysmon` EventCode=10 TargetImage=*\\lsass.exe granted_access IN ("0x01000", "0x1010", "0x1038", "0x40", "0x1400", "0x1fffff", "0x1410", "0x143a", "0x1438", "0x1000") CallTrace IN ("*dbgcore.dll*", "*dbghelp.dll*", "*ntdll.dll*", "*kernelbase.dll*", "*kernel32.dll*") NOT SourceUser IN ("NT AUTHORITY\\SYSTEM", "NT AUTHORITY\\NETWORK SERVICE") 
2| stats count min(_time) as firstTime max(_time) as lastTime by dest, SourceImage, GrantedAccess, TargetImage, SourceProcessId, SourceUser, TargetUser 
3| rename SourceUser as user 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `windows_possible_credential_dumping_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_possible_credential_dumping_filter search *
windows_possible_credential_dumping_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
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

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 0x1010 and 0x1400, filter based on source image as needed or remove them. Concern is Cobalt Strike usage of Mimikatz will generate 0x1010 initially, but later be caught.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

A process, $SourceImage$, has loaded $TargetImage$ that are typically related to credential dumping on $dest$. Review for further details.

Risk Object Risk Object Type Risk Score Threat Objects
user user 64 SourceImage
dest system 64 SourceImage

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: 7