Rundll32 with Suspicious Export Functionalities

SIGMA detection rule by Micah Babinski · GPL-3.0

Detects instances of rundll32.exe running Windows native DLLs that have export functionalities that adversaries commonly leverage for executing malicious code and evading defensive controls. Inspired by the 2022 Red Canary Threat Detection report.

title: Rundll32 with Suspicious Export Functionalities
id: e7cff8e3-89ae-47bd-841f-833e0a647f72
status: experimental
description: Detects instances of rundll32.exe running Windows native DLLs that have
    export functionalities that adversaries commonly leverage for executing malicious
    code and evading defensive controls. Inspired by the 2022 Red Canary Threat Detection
    report.
references:
    - https://redcanary.com/threat-detection-report/techniques/rundll32/
author: Micah Babinski
date: 2022/11/03
tags:
    - attack.defense_evasion
    - attack.t1218
    - attack.t1218.011
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\rundll32.exe'
        CommandLine|contains:
            - 'minidump'
            - 'startw'
    condition: selection
falsepositives:
    - Unknown
level: medium

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

6e71cfc9-9fad-4cea-a72c-40076a4fdb9f

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

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