Detection rules › Sigma
Potential Persistence Via Outlook Form
Detects the creation of a new Outlook form which can contain malicious code
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1137.003 Office Application Startup: Outlook Forms |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 11 | FileCreate |
Rule body yaml
title: Potential Persistence Via Outlook Form
id: c3edc6a5-d9d4-48d8-930e-aab518390917
status: test
description: Detects the creation of a new Outlook form which can contain malicious code
references:
- https://speakerdeck.com/heirhabarov/hunting-for-persistence-via-microsoft-exchange-server-or-outlook?slide=76
- https://speakerdeck.com/heirhabarov/hunting-for-persistence-via-microsoft-exchange-server-or-outlook?slide=79
- https://learn.microsoft.com/en-us/office/vba/outlook/concepts/outlook-forms/create-an-outlook-form
- https://www.slipstick.com/developer/custom-form/clean-outlooks-forms-cache/
author: Tobias Michalski (Nextron Systems)
date: 2021-06-10
modified: 2023-02-22
tags:
- attack.persistence
- attack.t1137.003
logsource:
product: windows
category: file_event
detection:
selection:
Image|endswith: '\outlook.exe'
TargetFilename|contains:
- '\AppData\Local\Microsoft\FORMS\IPM'
- '\Local Settings\Application Data\Microsoft\Forms' # Windows XP
condition: selection
falsepositives:
- Legitimate use of outlook forms
level: high
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
Image|endswith: '\outlook.exe'
TargetFilename|contains:
- '\AppData\Local\Microsoft\FORMS\IPM'
- '\Local Settings\Application Data\Microsoft\Forms'
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Image | ends_with |
|
TargetFilename | match |
|