Suspicious Rundll32 Setupapi.dll Activity

Status: test
Severity: medium
Log source: category process_creation, product windows
Author: Konstantin Grishchenko, oscd.community
Source: github.com/SigmaHQ/sigma

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.

Known false positives

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

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1218.011` System Binary Proxy Execution: Rundll32

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation

Rule body

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

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    Image|endswith: '\runonce.exe'
    ParentImage|endswith: '\rundll32.exe'
    ParentCommandLine|contains|all:
        - 'setupapi.dll'
        - 'InstallHinfSection'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Image`	ends_with	`\runonce.exe` corpus 3 (sigma 3)	`field:"Image" kind:ends_with value:"\runonce.exe"`
`ParentCommandLine`	match	`InstallHinfSection` `setupapi.dll`	`field:"ParentCommandLine" kind:match`
`ParentImage`	ends_with	`\rundll32.exe` corpus 15 (sigma 15)	`field:"ParentImage" kind:ends_with value:"\rundll32.exe"`