Detection rules › Sigma

Microsoft VBA For Outlook Addin Loaded Via Outlook

Status
test
Severity
medium
Log source
category image_load, product windows
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects outlvba (Microsoft VBA for Outlook Addin) DLL being loaded by the outlook process

Known false positives

  • Legitimate macro usage. Add the appropriate filter according to your environment

MITRE ATT&CK coverage

Telemetry coverage

ProviderRecord / event type
SysmonEvent ID 7: Image loaded

Rule body

title: Microsoft VBA For Outlook Addin Loaded Via Outlook
id: 9a0b8719-cd3c-4f0a-90de-765a4cb3f5ed
status: test
description: Detects outlvba (Microsoft VBA for Outlook Addin) DLL being loaded by the outlook process
references:
    - https://speakerdeck.com/heirhabarov/hunting-for-persistence-via-microsoft-exchange-server-or-outlook?slide=58
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-02-08
modified: 2024-03-12
tags:
    - attack.execution
    - attack.t1204.002
logsource:
    category: image_load
    product: windows
detection:
    selection:
        Image|endswith: '\outlook.exe'
        ImageLoaded|endswith: '\outlvba.dll'
    condition: selection
falsepositives:
    - Legitimate macro usage. Add the appropriate filter according to your environment
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    Image|endswith: '\outlook.exe'
    ImageLoaded|endswith: '\outlvba.dll'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Imageends_with
  • \outlook.exe corpus 13 (sigma 13)
field:"Image" kind:ends_with value:"\outlook.exe"
ImageLoadedends_with
  • \outlvba.dll
field:"ImageLoaded" kind:ends_with value:"\outlvba.dll"