Detection rules › Sigma
Windows native backup size re-configuration
Detects scenarios where an attacker attempts to delete existing Windows native backup by reducing the allocated backup storage.
Known false positives
- administrator cleaning outdated backup
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Impact |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Security-Auditing | Event ID 4688: A new process has been created. |
Rule body
title: Windows native backup size re-configuration
description: Detects scenarios where an attacker attempts to delete existing Windows native backup by reducing the allocated backup storage.
references:
- https://www.picussecurity.com/resource/blog/how-to-beat-nefilim-ransomware-attacks
- https://www.itechtics.com/volume-shadow-copies/
- https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/wbadmin
- https://www.picussecurity.com/resource/blog/technique-to-delete-volume-shadow-copies-deviceiocontrol
tags:
- attack.impact
- attack.t1490
author: mdecrevoisier
status: experimental
logsource:
product: windows
category: process_creation
detection:
selection: # vssadmin resize shadowstorage /for=c: /on=c: /maxsize=401MB
EventID: 4688
NewProcessName|endswith: \Windows\System32\vssadmin.exe
CommandLine|contains|all:
- resize
- shadowstorage
condition: selection
falsepositives:
- administrator cleaning outdated backup
level: high
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
EventID: 4688
NewProcessName|endswith: \Windows\System32\vssadmin.exe
CommandLine|contains|all:
- resize
- shadowstorage
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
CommandLine | match |
| field:"CommandLine" kind:match |
NewProcessName | ends_with |
| field:"Image" kind:ends_with value:"\Windows\System32\vssadmin.exe" |