sigmacriticalHunting

WMI Backdoor Exchange Transport Agent

Detects a WMI backdoor in Exchange Transport Agents via WMI event filters

MITRE ATT&CK

privilege-escalationpersistence

Detection Query

selection:
  ParentImage|endswith: \EdgeTransport.exe
filter_conhost:
  Image: C:\Windows\System32\conhost.exe
filter_oleconverter:
  Image|startswith: C:\Program Files\Microsoft\Exchange Server\
  Image|endswith: \Bin\OleConverter.exe
condition: selection and not 1 of filter_*

Author

Florian Roth (Nextron Systems)

Created

2019-10-11

Data Sources

windowsProcess Creation Events

Platforms

windows

References

Tags

attack.privilege-escalationattack.persistenceattack.t1546.003

Raw Content

title: WMI Backdoor Exchange Transport Agent
id: 797011dc-44f4-4e6f-9f10-a8ceefbe566b
status: test
description: Detects a WMI backdoor in Exchange Transport Agents via WMI event filters
references:
    - https://twitter.com/cglyer/status/1182389676876980224
    - https://twitter.com/cglyer/status/1182391019633029120
author: Florian Roth (Nextron Systems)
date: 2019-10-11
modified: 2023-02-08
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1546.003
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\EdgeTransport.exe'
    filter_conhost:
        Image: 'C:\Windows\System32\conhost.exe'
    filter_oleconverter:  # FP also documented in https://speakerdeck.com/heirhabarov/hunting-for-persistence-via-microsoft-exchange-server-or-outlook?slide=18
        Image|startswith: 'C:\Program Files\Microsoft\Exchange Server\'
        Image|endswith: '\Bin\OleConverter.exe'
    condition: selection and not 1 of filter_*
falsepositives:
    - Unknown
level: critical