Failed MSExchange Transport Agent Installation — Sigma Rule

Rule metadata and linked tags

Author: Tobias Michalski (Nextron Systems). Source status: test; severity: high. Source dates: 2021-06-08 / 2022-07-12.

{
  "service": "msexchange-management",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: d8dabf9fea7c0e5898da2332fde2e97513092be90f9797893f1fc98acb7f4d1b

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Failed MSExchange Transport Agent Installation
id: c7d16cae-aaf3-42e5-9c1c-fb8553faa6fa
status: test
description: Detects a failed installation of a Exchange Transport Agent
references:
    - https://speakerdeck.com/heirhabarov/hunting-for-persistence-via-microsoft-exchange-server-or-outlook?slide=8
author: Tobias Michalski (Nextron Systems)
date: 2021-06-08
modified: 2022-07-12
tags:
    - attack.persistence
    - attack.t1505.002
logsource:
    service: msexchange-management
    product: windows
    # warning: The 'data' field used in the detection section is the container for the event data as a whole. You may have to adapt the rule for your backend accordingly
detection:
    selection:
        EventID: 6
        Data|contains: 'Install-TransportAgent'
    condition: selection
falsepositives:
    - Legitimate installations of exchange TransportAgents. AssemblyPath is a good indicator for this.
level: high

Original YAML and metadata in JSON

False positives

• Legitimate installations of exchange TransportAgents. AssemblyPath is a good indicator for this.

Source references

• https://speakerdeck.com/heirhabarov/hunting-for-persistence-via-microsoft-exchange-server-or-outlook?slide=8