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.

Search

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	'xmlwineventlog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

Macros Used

Annotations

Default Configuration

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

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

• CISA AA22-257A

• CISA AA22-264A

• CISA AA23-347A

• Credential Dumping

• DarkSide Ransomware

• Detect Zerologon Attack

Risk Based Analytics (RBA)

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

• https://github.com/redcanaryco/AtomicTestHarnesses/blob/master/Windows/TestHarnesses/T1003.001_DumpLSASS/DumpLSASS.ps1

Detection Testing

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: 6