Delete ShadowCopy With PowerShell

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Description

The following analytic detects the use of PowerShell to delete shadow copies via the WMIC PowerShell module. It leverages EventCode 4104 and searches for specific keywords like "ShadowCopy," "Delete," or "Remove" within the ScriptBlockText. This activity is significant because deleting shadow copies is a common tactic used by ransomware, such as DarkSide, to prevent data recovery. If confirmed malicious, this action could lead to irreversible data loss and hinder recovery efforts, significantly impacting business continuity and data integrity.

• Type: TTP

• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

• Last Updated: 2024-05-23
• Author: Teoderick Contreras, Splunk
• ID: 5ee2bcd0-b2ff-11eb-bb34-acde48001122

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1490	Inhibit System Recovery	Impact

Kill Chain Phase

• Actions On Objectives

NIST

• DE.CM

CIS20

• CIS 10

CVE

Search

`powershell` EventCode=4104 ScriptBlockText= "*ShadowCopy*" (ScriptBlockText = "*Delete*" OR ScriptBlockText = "*Remove*") 
| stats count min(_time) as firstTime max(_time) as lastTime by Opcode Computer UserID EventCode ScriptBlockText 
|rename Computer as dest 
|rename UserID as user 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `delete_shadowcopy_with_powershell_filter`

Macros

The SPL above uses the following Macros:

• powershell
• security_content_ctime

delete_shadowcopy_with_powershell_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

• _time
• ScriptBlockText
• Opcode
• Computer
• UserID
• EventCode

How To Implement

To successfully implement this search, you need to be ingesting logs with the powershell logs from your endpoints. make sure you enable needed registry to monitor this event.

Known False Positives

unknown

Associated Analytic Story

• DarkSide Ransomware
• Ransomware
• Revil Ransomware
• DarkGate Malware

RBA

Risk Score	Impact	Confidence	Message
81.0	90	90	An attempt to delete ShadowCopy was performed using PowerShell on $dest$ by $user$.

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

• https://www.mandiant.com/resources/shining-a-light-on-darkside-ransomware-operations
• https://www.techtarget.com/searchwindowsserver/tutorial/Set-up-PowerShell-script-block-logging-for-added-security

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

source | version: 3