Windows Registry: Detect esentutl.exe activity under VSS service keys

Flags registry changes under VSS service keys when initiated by esentutl.exe, consistent with VSS-related abuse.

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windows-registry-detect-esentutl-exe-activity-under-vss-service-keys-5aad0995

title: "Windows Registry: Detect esentutl.exe activity under VSS service keys"
id: 57b8cba7-f2d1-4250-85fd-1f2899afa7a7
status: test
description: This rule identifies Windows registry activity involving the Volume Shadow Copy Service (VSS) service subtree when the initiating process is esentutl.exe. Attackers may use VSS-related functionality to support credential access and other post-compromise objectives, making service initialization and processing relevant. It relies on registry event telemetry that records the TargetObject being modified and the Image path for the process (filtered to exclude Start-related entries).
references:
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1003.002/T1003.002.md#atomic-test-3---esentutlexe-sam-copy
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/registry/registry_event/registry_event_esentutl_volume_shadow_copy_service_keys.yml
author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research), Huntrule Team
date: 2020-10-20
modified: 2022-12-25
tags:
  - attack.credential-access
  - attack.t1003.002
logsource:
  category: registry_event
  product: windows
detection:
  selection:
    TargetObject|contains: System\CurrentControlSet\Services\VSS
    Image|endswith: esentutl.exe
  filter:
    TargetObject|contains: System\CurrentControlSet\Services\VSS\Start
  condition: selection and not filter
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: 5aad0995-46ab-41bd-a9ff-724f41114971
    type: derived

What it detects

This rule identifies Windows registry activity involving the Volume Shadow Copy Service (VSS) service subtree when the initiating process is esentutl.exe. Attackers may use VSS-related functionality to support credential access and other post-compromise objectives, making service initialization and processing relevant. It relies on registry event telemetry that records the TargetObject being modified and the Image path for the process (filtered to exclude Start-related entries).

Known false positives

Unknown

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.