Detection: Windows Eventlog Cleared Via Wevtutil

Updated Date: 2026-09-21 ID: fdb829a8-db84-4832-b64b-3e964cd44f01 Author: Nasreddine Bencherchali, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects the usage of wevtutil.exe with the "clear-log" parameter in order to clear the contents of logs. Clearing the event logs can be an attempt to cover tracks after malicious actions, hindering forensic investigations.

Search

 1
 2| tstats `security_content_summariesonly`
 3  count values(Processes.process) as process
 4        min(_time) as firstTime
 5        max(_time) as lastTime
 6
 7FROM datamodel=Endpoint.Processes WHERE
 8
 9Processes.process_name=wevtutil.exe
10Processes.process IN ("* cl *", "*clear-log*")

We exclude the following strings to avoid detection overlap and double coverage since they are already covered by the "Suspicious wevtutil Usage" detection.

 1NOT Processes.process IN (
 2    "*/Trace*",
 3    "*AMSI/Debug*",
 4    "*Application*",
 5    "*CiscoSecureEndpoint*",
 6    "*Microsoft-Windows-BitLocker*",
 7    "*Microsoft-Windows-Bits*",
 8    "*Microsoft-Windows-CAPI2*",
 9    "*Microsoft-Windows-Kernel-File*",
10    "*Microsoft-Windows-Kernel-Process*",
11    "*Microsoft-Windows-LDAP*",
12    "*Microsoft-Windows-PowerShell*",
13    "*Microsoft-Windows-Sysmon*",
14    "*Microsoft-Windows-TerminalServices-LocalSessionManager*",
15    "*Microsoft-Windows-TerminalServices-RemoteConnectionManager*",
16    "*Microsoft-Windows-WMI-Activity*",
17    "*OpenSSH/*",
18    "*PowerShellCore/*",
19    "*Security*",
20    "*Setup*",
21    "*System*",
22    "*Windows Firewall With Advanced Security*",
23    "*Windows PowerShell*"
24)
25
26BY Processes.action Processes.dest Processes.original_file_name
27   Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
28   Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
29   Processes.process Processes.process_exec Processes.process_guid
30   Processes.process_hash Processes.process_id Processes.process_integrity_level
31   Processes.process_name Processes.process_path Processes.user
32   Processes.user_id Processes.vendor_product
33
34
35| `drop_dm_object_name(Processes)`
36
37| `security_content_ctime(firstTime)`
38
39| `security_content_ctime(lastTime)`
40
41| `windows_eventlog_cleared_via_wevtutil_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	Other	`'crowdstrike:events:sensor'`	`'crowdstrike'`
Windows Event Log Security 4688	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Security'`
Sysmon EventID 1	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`

Macros Used

Name	Value
security_content_summariesonly	`summariesonly=`summariesonly_config `allow_old_summaries=`oldsummaries_config `fillnull_value=`fillnull_config``
windows_eventlog_cleared_via_wevtutil_filter	`search *`

windows_eventlog_cleared_via_wevtutil_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.AE

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)	No
Creates Intermediate Finding (Risk Event)	Yes

Anomaly detections generate Intermediate Findings (Risk Events). They do not generate a Finding (Notable) directly.

Implementation

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

The wevtutil.exe application is a legitimate Windows event log utility. Administrators may use it to manage Windows event logs.

Associated Analytic Story

Intermediate Findings

Message	Entity Field	Entity Type	Risk Score
The EventLog was cleared using the [$process_name$] utility with the Command Line [$process$] on [$dest$] by [$user$].	dest	system	20

Threat Objects

Field	Type
process	process

References

https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1070.001/T1070.001.md

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