Windows CertReq -Post Download Attempt via HTTP

Flags certreq.exe executions using -Post -config and HTTP content retrieval indicators.

FreeReviewedSigma · High · v2

Product: windows
Category: process_creation
Author: Christian Burkard (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2021-11-24
Updated: 2026-07-31

ATT&CK techniques

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1105Ingress Tool Transfer
Exfiltration
Impact

What it detects

Identifies execution of certreq.exe where the command line includes the -Post option and a -config argument, along with an HTTP URL. This pattern can be used to retrieve additional content or configuration through certreq, which is a legitimate Windows certificate utility that attackers may repurpose for command-and-control style payload retrieval. The detection relies on Windows process creation telemetry with command-line arguments and process image/original filename metadata.

Reporting behind it

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Windows CertReq -Post Download Attempt via HTTP

Pivot detection · T1105 · 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-certreq-exe-certreq-post-download-execution-4480827a

title: Windows CertReq -Post Download Attempt via HTTP
id: 4d12bfd1-8edc-4b0e-86b5-d647057d13e5
status: experimental
description: Identifies execution of certreq.exe where the command line includes the -Post option and a -config argument, along with an HTTP URL. This pattern can be used to retrieve additional content or configuration through certreq, which is a legitimate Windows certificate utility that attackers may repurpose for command-and-control style payload retrieval. The detection relies on Windows process creation telemetry with command-line arguments and process image/original filename metadata.
references:
  - https://lolbas-project.github.io/lolbas/Binaries/Certreq/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_certreq_download.yml
author: Christian Burkard (Nextron Systems), Huntrule Team
date: 2021-11-24
modified: 2025-10-29
tags:
  - attack.command-and-control
  - attack.t1105
logsource:
  category: process_creation
  product: windows
detection:
  selection_img:
    - Image|endswith: \certreq.exe
    - OriginalFileName: CertReq.exe
  selection_cli_flag_post:
    CommandLine|contains|windash: -Post
  selection_cli_flag_config:
    CommandLine|contains|windash: -config
  selection_cli_http:
    CommandLine|contains: http
  condition: all of selection_*
falsepositives:
  - Unlikely
level: high
license: DRL-1.1
related:
  - id: 4480827a-9799-4232-b2c4-ccc6c4e9e12b
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

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