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Description

This following analytic detects PowerShell command to delete shadow copy using the WMIC PowerShell module. This technique was seen used by a recent adversary to deploy DarkSide Ransomware where it executed a child process of PowerShell to execute a hex encoded command to delete shadow copy. This hex encoded command was able to be decrypted by PowerShell log.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2022-05-02
  • 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
  • Exploitation
NIST
CIS20
CVE
1
2
3
4
5
`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 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `delete_shadowcopy_with_powershell_filter`

Macros

The SPL above uses the following Macros:

:information_source: 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

RBA

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

:information_source: 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

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: 2