splunk-security_content/docs/_posts/2021-10-11-suspicious_wevtutil_usage.md

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title	excerpt	categories	last_modified_at	toc	toc_label	tags
Suspicious wevtutil Usage	Clear Windows Event Logs, Indicator Removal on Host	Endpoint	2021-10-11	true		Clear Windows Event Logs Defense Evasion Indicator Removal on Host Defense Evasion Splunk Enterprise Splunk Enterprise Security Splunk Cloud Endpoint

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Description

The wevtutil.exe application is the windows event log utility. This searches for wevtutil.exe with parameters for clearing the application, security, setup, trace or system event logs.

• Type: TTP
• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
• Datamodel: Endpoint
• Last Updated: 2021-10-11
• Author: David Dorsey, Michael Haag, Splunk
• ID: 2827c0fd-e1be-4868-ae25-59d28e0f9d4f

ATT&CK

ID	Technique	Tactic
T1070.001	Clear Windows Event Logs	Defense Evasion

| T1070 | Indicator Removal on Host | Defense Evasion |

Search

| tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name=wevtutil.exe Processes.process IN ("* cl *", "*clear-log*") (Processes.process="*System*" OR Processes.process="*Security*" OR Processes.process="*Setup*" OR Processes.process="*Application*" OR Processes.process="*trace*") by Processes.process_name Processes.parent_process_name Processes.dest Processes.user
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
|`security_content_ctime(lastTime)` 
| `suspicious_wevtutil_usage_filter`

Associated Analytic Story

• Windows Log Manipulation
• Ransomware
• Clop Ransomware

How To Implement

You must be ingesting data that records process activity from your hosts to populate the Endpoint data model in the Processes node. You must also be ingesting logs with both the process name and command line from your endpoints. The command-line arguments are mapped to the "process" field in the Endpoint data model.

Required field

• _time
• Processes.process
• Processes.process_name
• Processes.parent_process_name
• Processes.dest
• Processes.user

Kill Chain Phase

• Actions on Objectives

Known False Positives

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

RBA

Risk Score	Impact	Confidence	Message
28.0	40	70	Wevtutil.exe being used to clear Event Logs on dest by user

Reference

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

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

• https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1070.001/atomic_red_team/windows-sysmon.log

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