PowerShell Script with Log Clear Capabilitiesedit
Identifies the use of Cmdlets and methods related to Windows event log deletion activities. This is often done by attackers in an attempt to evade detection or destroy forensic evidence on a system.
Rule type: query
Rule indices:
- winlogbeat-*
- logs-windows.powershell*
Severity: low
Risk score: 21
Runs every: 60m
Searches indices from: now-119m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Defense Evasion
- Data Source: PowerShell Logs
- Rule Type: BBR
Version: 105
Rule authors:
- Elastic
Rule license: Elastic License v2
Setupedit
Setup
The PowerShell Script Block Logging logging policy must be enabled. Steps to implement the logging policy with Advanced Audit Configuration:
Computer Configuration > Administrative Templates > Windows PowerShell > Turn on PowerShell Script Block Logging (Enable)
Steps to implement the logging policy via registry:
reg add "hklm\SOFTWARE\Policies\Microsoft\Windows\PowerShell\ScriptBlockLogging" /v EnableScriptBlockLogging /t REG_DWORD /d 1
Rule queryedit
event.category:process and host.os.type:windows and
powershell.file.script_block_text : (
"Clear-EventLog" or
"Remove-EventLog" or
("Eventing.Reader.EventLogSession" and ".ClearLog") or
("Diagnostics.EventLog" and ".Clear")
) and
not powershell.file.script_block_text : (
"CmdletsToExport=@(\"Add-Content\""
)
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: Indicator Removal
- ID: T1070
- Reference URL: https://attack.mitre.org/techniques/T1070/
-
Sub-technique:
- Name: Clear Windows Event Logs
- ID: T1070.001
- Reference URL: https://attack.mitre.org/techniques/T1070/001/
-
Tactic:
- Name: Execution
- ID: TA0002
- Reference URL: https://attack.mitre.org/tactics/TA0002/
-
Technique:
- Name: Command and Scripting Interpreter
- ID: T1059
- Reference URL: https://attack.mitre.org/techniques/T1059/
-
Sub-technique:
- Name: PowerShell
- ID: T1059.001
- Reference URL: https://attack.mitre.org/techniques/T1059/001/