Windows Process: curl Download with HTTP Output Redirect and Command Chaining

Flags Windows commands where curl downloads over HTTP with -o and then executes via command chaining with '&'.

FreeReviewedSigma · High · v2

Product: windows
Category: process_creation
Author: Sreeman, Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2020-01-13
Updated: 2026-07-31

ATT&CK techniques

Defense Evasion → C2

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1218System Binary Proxy Execution
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1105Ingress Tool Transfer
Exfiltration
Impact

What it detects

This rule identifies Windows process executions where the command line contains curl usage over HTTP, redirects output to a file (via -o), and then chains additional commands using an ampersand. Attackers often use curl in this pattern to retrieve a remote payload and immediately act on it within the same command context. It relies on process creation telemetry, specifically the process command line contents that include the relevant flags and delimiters.

Reporting behind it

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Windows Process: curl Download with HTTP Output Redirect and Command Chaining

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-curl-command-line-download-followed-by-execution-via-and-output-redirect-21dd6d38

title: "Windows Process: curl Download with HTTP Output Redirect and Command Chaining"
id: bfd33ec1-f188-44f6-b5e9-b9b5d305d2d7
status: test
description: This rule identifies Windows process executions where the command line contains curl usage over HTTP, redirects output to a file (via -o), and then chains additional commands using an ampersand. Attackers often use curl in this pattern to retrieve a remote payload and immediately act on it within the same command context. It relies on process creation telemetry, specifically the process command line contents that include the relevant flags and delimiters.
references:
  - https://medium.com/@reegun/curl-exe-is-the-new-rundll32-exe-lolbin-3f79c5f35983
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_cmd_curl_download_exec_combo.yml
author: Sreeman, Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2020-01-13
modified: 2024-03-05
tags:
  - attack.stealth
  - attack.t1218
  - attack.command-and-control
  - attack.t1105
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    CommandLine|contains|windash: " -c "
    CommandLine|contains|all:
      - "curl "
      - http
      - -o
      - "&"
  condition: selection
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: 21dd6d38-2b18-4453-9404-a0fe4a0cc288
    type: derived

Convert

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