Detection rules › Sigma
Suspicious Outlook Macro Created
Detects the creation of a macro file for Outlook.
Known false positives
- Unlikely
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | |
| Privilege Escalation | |
| Command & Control |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 11: FileCreate |
Rule body
title: Suspicious Outlook Macro Created
id: 117d3d3a-755c-4a61-b23e-9171146d094c
related:
- id: 8c31f563-f9a7-450c-bfa8-35f8f32f1f61
type: derived
status: test
description: Detects the creation of a macro file for Outlook.
references:
- https://www.mdsec.co.uk/2020/11/a-fresh-outlook-on-mail-based-persistence/
- https://speakerdeck.com/heirhabarov/hunting-for-persistence-via-microsoft-exchange-server-or-outlook?slide=53
- https://www.linkedin.com/pulse/outlook-backdoor-using-vba-samir-b-/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-02-08
tags:
- attack.privilege-escalation
- attack.persistence
- attack.command-and-control
- attack.t1137
- attack.t1008
- attack.t1546
logsource:
category: file_event
product: windows
detection:
selection:
TargetFilename|endswith: '\Microsoft\Outlook\VbaProject.OTM'
filter:
Image|endswith: '\outlook.exe'
condition: selection and not filter
falsepositives:
- Unlikely
level: high
Stages and Predicates
Stage 0: condition
selection and not filterStage 1: selection
selection:
TargetFilename|endswith: '\Microsoft\Outlook\VbaProject.OTM'
Stage 2: not filter
filter:
Image|endswith: '\outlook.exe'
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
Image | ends_with | \outlook.exe | excludes:Image field:"Image" value:"\outlook.exe" |
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
TargetFilename | ends_with |
| field:"TargetFilename" kind:ends_with value:"\Microsoft\Outlook\VbaProject.OTM" |