Detection rules › Sigma

Windows Backup Deleted Via Wbadmin.EXE

Status
test
Severity
medium
Log source
product windows, category process_creation
Author
frack113, Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects the deletion of backups or system state backups via "wbadmin.exe". This technique is used by numerous ransomware families and actors. This may only be successful on server platforms that have Windows Backup enabled.

MITRE ATT&CK coverage

TacticTechniques
ImpactT1490 Inhibit System Recovery

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: Windows Backup Deleted Via Wbadmin.EXE
id: 89f75308-5b1b-4390-b2d8-d6b2340efaf8
related:
    - id: 639c9081-f482-47d3-a0bd-ddee3d4ecd76
      type: derived
status: test
description: |
    Detects the deletion of backups or system state backups via "wbadmin.exe".
    This technique is used by numerous ransomware families and actors.
    This may only be successful on server platforms that have Windows Backup enabled.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1490/T1490.md#atomic-test-5---windows---delete-volume-shadow-copies-via-wmi-with-powershell
    - https://github.com/albertzsigovits/malware-notes/blob/558898932c1579ff589290092a2c8febefc3a4c9/Ransomware/Lockbit.md
    - https://www.sentinelone.com/labs/ranzy-ransomware-better-encryption-among-new-features-of-thunderx-derivative/
    - https://www.trendmicro.com/vinfo/us/security/news/cybercrime-and-digital-threats/ransomware-report-avaddon-and-new-techniques-emerge-industrial-sector-targeted
    - https://www.trendmicro.com/content/dam/trendmicro/global/en/research/24/b/lockbit-attempts-to-stay-afloat-with-a-new-version/technical-appendix-lockbit-ng-dev-analysis.pdf
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/wbadmin-delete-systemstatebackup
author: frack113, Nasreddine Bencherchali (Nextron Systems)
date: 2021-12-13
modified: 2024-05-10
tags:
    - attack.impact
    - attack.t1490
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\wbadmin.exe'
        - OriginalFileName: 'WBADMIN.EXE'
    selection_cli:
        CommandLine|contains|all:
            - 'delete '
            - 'backup' # Also covers "SYSTEMSTATEBACKUP"
    filter_main_keep_versions:
        # Note: We exclude this to avoid duplicate alerts with 639c9081-f482-47d3-a0bd-ddee3d4ecd76
        CommandLine|contains: 'keepVersions:0'
    condition: all of selection_* and not 1 of filter_main_*
falsepositives:
    - Legitimate backup activity from administration scripts and software.
level: medium

Stages and Predicates

Stage 0: condition

all of selection_* and not 1 of filter_main_*

Stage 1: selection_img

selection_img:
    - Image|endswith: '\wbadmin.exe'
    - OriginalFileName: 'WBADMIN.EXE'

Stage 2: selection_cli

selection_cli:
    CommandLine|contains|all:
        - 'delete '
        - 'backup'

Stage 3: not filter_main_keep_versions

filter_main_keep_versions:
    CommandLine|contains: 'keepVersions:0'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
CommandLinematchkeepVersions:0

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
CommandLinematch
  • backup corpus 6 (sigma 5, splunk 1)
  • delete corpus 4 (sigma 4)
Imageends_with
  • \wbadmin.exe corpus 7 (sigma 7)
OriginalFileNameeq
  • WBADMIN.EXE corpus 10 (sigma 6, elastic 2, splunk 2)