VMGuestLib DLL Sideload

 1title: VMGuestLib DLL Sideload
 2id: 70e8e9b4-6a93-4cb7-8cde-da69502e7aff
 3status: test
 4description: Detects DLL sideloading of VMGuestLib.dll by the WmiApSrv service.
 5references:
 6    - https://decoded.avast.io/martinchlumecky/png-steganography/
 7author: Nasreddine Bencherchali (Nextron Systems)
 8date: 2022-12-01
 9tags:
10    - attack.defense-evasion
11    - attack.persistence
12    - attack.privilege-escalation
13    - attack.t1574.001
14logsource:
15    category: image_load
16    product: windows
17detection:
18    selection:
19        ImageLoaded|contains|all:
20            - '\VMware\VMware Tools\vmStatsProvider\win32'
21            - '\vmGuestLib.dll'
22        Image|endswith: '\Windows\System32\wbem\WmiApSrv.exe'
23    filter:
24        Signed: 'true'
25    condition: selection and not filter
26falsepositives:
27    - FP could occur if the legitimate version of vmGuestLib already exists on the system
28level: medium

References

• PNG Steganography Hides Backdoor - Avast Threat Labs

  

  Our deep analysis of the Worok toolset (previously described by ESET Research) reveals the final stage, hidden in a PNG file, that steals data and provides a multifunctional backdoor using the DropBox repository and API.

  
  Read More

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