Delete ShadowCopy With PowerShell
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
- Last Updated: 2022-05-02
- Author: Teoderick Contreras, Splunk
- ID: 5ee2bcd0-b2ff-11eb-bb34-acde48001122
Annotations
Kill Chain Phase
- Actions On Objectives
NIST
- DE.CM
CIS20
- CIS 10
CVE
Search
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`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:
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 $User$. |
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: 2