Suspicious Rundll32 Setupapi.dll Activity — Sigma Rule

Rule metadata and linked tags

Author: Konstantin Grishchenko, oscd.community. Source status: test; severity: medium. Source dates: 2020-10-07 / 2021-11-27.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: b36a729254908add117fd9ed21280389adb9bc2a86257c1c6235b6d5927d1c44

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: Suspicious Rundll32 Setupapi.dll Activity
id: 285b85b1-a555-4095-8652-a8a4106af63f
status: test
description: setupapi.dll library provide InstallHinfSection function for processing INF files. INF file may contain instructions allowing to create values in the registry, modify files and install drivers. This technique could be used to obtain persistence via modifying one of Run or RunOnce registry keys, run process or use other DLLs chain calls (see references) InstallHinfSection function in setupapi.dll calls runonce.exe executable regardless of actual content of INF file.
references:
    - https://lolbas-project.github.io/lolbas/Libraries/Setupapi/
    - https://gist.githubusercontent.com/bohops/0cc6586f205f3691e04a1ebf1806aabd/raw/baf7b29891bb91e76198e30889fbf7d6642e8974/calc_exe.inf
    - https://raw.githubusercontent.com/huntresslabs/evading-autoruns/master/shady.inf
    - https://twitter.com/Z3Jpa29z/status/1313742350292746241?s=20
author: Konstantin Grishchenko, oscd.community
date: 2020-10-07
modified: 2021-11-27
tags:
    - attack.stealth
    - attack.t1218.011
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\runonce.exe'
        ParentImage|endswith: '\rundll32.exe'
        ParentCommandLine|contains|all:
            - 'setupapi.dll'
            - 'InstallHinfSection'
    condition: selection
falsepositives:
    - Scripts and administrative tools that use INF files for driver installation with setupapi.dll
level: medium

Original YAML and metadata in JSON

False positives

• Scripts and administrative tools that use INF files for driver installation with setupapi.dll

Source references

• https://lolbas-project.github.io/lolbas/Libraries/Setupapi/
• https://gist.githubusercontent.com/bohops/0cc6586f205f3691e04a1ebf1806aabd/raw/baf7b29891bb91e76198e30889fbf7d6642e8974/calc_exe.inf
• https://raw.githubusercontent.com/huntresslabs/evading-autoruns/master/shady.inf
• https://twitter.com/Z3Jpa29z/status/1313742350292746241?s=20