Esentutl Volume Shadow Copy Service Keys

Status: test
Severity: high
Log source: category registry_event, product windows
Author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research)
Source: github.com/SigmaHQ/sigma

Detects the volume shadow copy service initialization and processing via esentutl. Registry keys such as HKLM\System\CurrentControlSet\Services\VSS\Diag\VolSnap\Volume are captured.

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1003.002` OS Credential Dumping: Security Account Manager

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 12: RegistryEvent (Object create and delete)
Sysmon	Event ID 13: RegistryEvent (Value Set)
Sysmon	Event ID 14: RegistryEvent (Key and Value Rename)

Rule body

title: Esentutl Volume Shadow Copy Service Keys
id: 5aad0995-46ab-41bd-a9ff-724f41114971
status: test
description: Detects the volume shadow copy service initialization and processing via esentutl. Registry keys such as HKLM\\System\\CurrentControlSet\\Services\\VSS\\Diag\\VolSnap\\Volume are captured.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1003.002/T1003.002.md#atomic-test-3---esentutlexe-sam-copy
author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research)
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' # limit esentutl as in references, too many FP to filter
    filter:
        TargetObject|contains: 'System\CurrentControlSet\Services\VSS\Start'
    condition: selection and not filter
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: `condition`

selection and not filter

Stage 1: `selection`

selection:
    TargetObject|contains: 'System\CurrentControlSet\Services\VSS'
    Image|endswith: 'esentutl.exe'

Stage 2: `not filter`

filter:
    TargetObject|contains: 'System\CurrentControlSet\Services\VSS\Start'

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`TargetObject`	match	`System\CurrentControlSet\Services\VSS\Start`	`excludes:TargetObject` `field:"TargetObject" value:"System\CurrentControlSet\Services\VSS\Start"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Image`	ends_with	`esentutl.exe`	`field:"Image" kind:ends_with value:"esentutl.exe"`
`TargetObject`	match	`System\CurrentControlSet\Services\VSS`	`field:"TargetObject" kind:match value:"System\CurrentControlSet\Services\VSS"`