Detect Mimikatz Via PowerShell And EventCode 4703
THIS IS A DEPRECATED DETECTION
This detection has been marked deprecated by the Splunk Threat Research team. This means that it will no longer be maintained or supported.
Description
This search looks for PowerShell requesting privileges consistent with credential dumping. Deprecated, looks like things changed from a logging perspective.
- Type: TTP
-
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2024-08-15
- Author: Rico Valdez, Splunk
- ID: 98917be2-bfc8-475a-8618-a9bb06575188
Annotations
Kill Chain Phase
- Exploitation
NIST
- DE.CM
CIS20
- CIS 10
CVE
Search
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`wineventlog_security` signature_id=4703 Process_Name=*powershell.exe
| rex field=Message "Enabled Privileges:\s+(?<privs>\w+)\s+Disabled Privileges:"
| where privs="SeDebugPrivilege"
| stats count min(_time) as firstTime max(_time) as lastTime by dest, Process_Name, privs, Process_ID, Message
| rename privs as "Enabled Privilege"
| rename Process_Name as process
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `detect_mimikatz_via_powershell_and_eventcode_4703_filter`
Macros
The SPL above uses the following Macros:
detect_mimikatz_via_powershell_and_eventcode_4703_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Required fields
List of fields required to use this analytic.
- _time
- signature_id
- Process_Name
- Message
- dest
- Process_ID
How To Implement
You must be ingesting Windows Security logs. You must also enable the account change auditing here: http://docs.splunk.com/Documentation/Splunk/7.0.2/Data/MonitorWindowseventlogdata. Additionally, this search requires you to enable your Group Management Audit Logs in your Local Windows Security Policy and to be ingesting those logs. More information on how to enable them can be found here: http://whatevernetworks.com/auditing-group-membership-changes-in-active-directory/. Finally, please make sure that the local administrator group name is "Administrators" to be able to look for the right group membership changes.
Known False Positives
The activity may be legitimate. PowerShell is often used by administrators to perform various tasks, and it's possible this event could be generated in those cases. In these cases, false positives should be fairly obvious and you may need to tweak the search to eliminate noise.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
25.0 | 50 | 50 | tbd |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
Reference
Test Dataset
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 | version: 3