Detection rules › Sigma
VMGuestLib DLL Sideload
Detects DLL sideloading of VMGuestLib.dll by the WmiApSrv service.
Known false positives
- FP could occur if the legitimate version of vmGuestLib already exists on the system
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | |
| Stealth |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 7: Image loaded |
Rule body
title: VMGuestLib DLL Sideload
id: 70e8e9b4-6a93-4cb7-8cde-da69502e7aff
status: test
description: Detects DLL sideloading of VMGuestLib.dll by the WmiApSrv service.
references:
- https://decoded.avast.io/martinchlumecky/png-steganography/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-12-01
tags:
- attack.persistence
- attack.privilege-escalation
- attack.execution
- attack.stealth
- attack.t1574.001
logsource:
category: image_load
product: windows
detection:
selection:
ImageLoaded|contains|all:
- '\VMware\VMware Tools\vmStatsProvider\win32'
- '\vmGuestLib.dll'
Image|endswith: '\Windows\System32\wbem\WmiApSrv.exe'
filter:
Signed: 'true'
condition: selection and not filter
falsepositives:
- FP could occur if the legitimate version of vmGuestLib already exists on the system
level: medium
Stages and Predicates
Stage 0: condition
selection and not filterStage 1: selection
selection:
ImageLoaded|contains|all:
- '\VMware\VMware Tools\vmStatsProvider\win32'
- '\vmGuestLib.dll'
Image|endswith: '\Windows\System32\wbem\WmiApSrv.exe'
Stage 2: not filter
filter:
Signed: 'true'
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
Signed | eq | true | excludes:Signed field:"Signed" value:"true" |
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
Image | ends_with |
| field:"Image" kind:ends_with value:"\Windows\System32\wbem\WmiApSrv.exe" |
ImageLoaded | match |
| field:"ImageLoaded" kind:match |