Windows: CertOC.exe certificate utility loading a DLL via -LoadDLL

Flags CertOC.exe launching with -LoadDLL to load a specified DLL on Windows.

FreeReviewedSigma · Medium · v2

Product: windows
Category: process_creation
Author: Austin Songer @austinsonger (SigmaHQ), DRL 1.1
Published: 2021-10-23
Updated: 2026-07-31

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1218System Binary Proxy Execution
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags process creation events where CertOC.exe is launched and the command line contains the DLL-loading switch " -LoadDLL ". Attackers may use CertOC.exe to execute or load external DLL content, helping them blend into legitimate Windows utility activity. It relies on Windows process creation telemetry with Image or OriginalFileName plus the command line string match.

Reporting behind it

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Windows: CertOC.exe certificate utility loading a DLL via -LoadDLL

Pivot detection · T1218 · 9 related

Changelog

v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

windows-certoc-exe-loads-dll-via-loaddll-argument-242301bc

title: "Windows: CertOC.exe certificate utility loading a DLL via -LoadDLL"
id: 1571ebb8-5879-4639-8247-cbd1f290d959
related:
  - id: 84232095-ecca-4015-b0d7-7726507ee793
    type: similar
  - id: 242301bc-f92f-4476-8718-78004a6efd9f
    type: derived
status: test
description: This rule flags process creation events where CertOC.exe is launched and the command line contains the DLL-loading switch " -LoadDLL ". Attackers may use CertOC.exe to execute or load external DLL content, helping them blend into legitimate Windows utility activity. It relies on Windows process creation telemetry with Image or OriginalFileName plus the command line string match.
references:
  - https://twitter.com/sblmsrsn/status/1445758411803480072?s=20
  - https://github.com/elastic/protections-artifacts/commit/746086721fd385d9f5c6647cada1788db4aea95f#diff-fe98e74189873d6df72a15df2eaa0315c59ba9cdaca93ecd68afc4ea09194ef2
  - https://lolbas-project.github.io/lolbas/Binaries/Certoc/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_certoc_load_dll.yml
author: Austin Songer @austinsonger, Huntrule Team
date: 2021-10-23
modified: 2024-03-05
tags:
  - attack.stealth
  - attack.t1218
logsource:
  category: process_creation
  product: windows
detection:
  selection_img:
    - Image|endswith: \certoc.exe
    - OriginalFileName: CertOC.exe
  selection_cli:
    CommandLine|contains|windash: " -LoadDLL "
  condition: all of selection_*
falsepositives:
  - Unknown
level: medium
license: DRL-1.1

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