Detection: Windows Event Log Cleared

Description

The following analytic detects the clearing of Windows event logs by identifying Windows Security Event ID 1102 or System log event 104. This detection leverages Windows event logs to monitor for log clearing activities. Such behavior is significant as it may indicate an attempt to cover tracks after malicious activities. If confirmed malicious, this action could hinder forensic investigations and allow attackers to persist undetected, making it crucial to investigate further and correlate with other alerts and data sources.

 1(`wineventlog_security` EventCode=1102)
 2OR
 3(`wineventlog_system` EventCode=104)
 4
 5| stats count min(_time) as firstTime max(_time) as lastTime
 6  by action change_type dest dvc object_category signature_id status user vendor_product object EventCode
 7
 8| `security_content_ctime(firstTime)`
 9
10| `security_content_ctime(lastTime)`
11
12| `windows_event_log_cleared_filter`

Data Source

Name Platform Sourcetype Source
Windows Event Log System 104 Windows icon Windows 'XmlWinEventLog' 'XmlWinEventLog:System'
Windows Event Log Security 1102 Windows icon Windows 'XmlWinEventLog' 'XmlWinEventLog:Security'

Macros Used

Name Value
wineventlog_security eventtype="wineventlog_security" OR Channel="security" OR source="XmlWinEventLog:Security" OR source="WinEventLog:Security"
windows_event_log_cleared_filter search *
windows_event_log_cleared_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
T1685.005 Clear Windows Event Logs Defense Impairment
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 Finding (Notable) Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Intermediate Finding (Risk Event) No
TTP detections generate a Finding (Notable) and may generate Intermediate Findings (Risk Events) for associated entities.

Implementation

To successfully implement this search, you need to be ingesting Windows event logs from your hosts. In addition, the Splunk Windows TA is needed.

Known False Positives

It is possible that these logs may be legitimately cleared by Administrators. Filter as needed.

Associated Analytic Story

Finding

Title Entity Field Entity Type Risk Score
Windows $object$ cleared on $dest$ via EventCode $EventCode$ dest system 50

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation Passing N/A N/A N/A
Unit Passing Dataset XmlWinEventLog:Security XmlWinEventLog
Integration ✅ Passing Dataset XmlWinEventLog:Security 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: 20