huntrule

Windows: Unusual Child Process Spawned by dns.exe

Alerts when dns.exe launches an unexpected child process other than conhost.exe.

FreeUnreviewedSigmahighv1
title: "Windows: Unusual Child Process Spawned by dns.exe"
id: 6766c383-2fce-4cd0-89dc-69082bf8344b
status: test
description: This rule flags process creation events where dns.exe spawns a child process that does not match the expected conhost.exe exception. Unexpected child processes from dns.exe can indicate compromised host activity, including exploitation workflows that rely on launching additional binaries. It relies on Windows process creation telemetry, matching the parent image by name and observing the spawned child process.
references:
  - https://www.elastic.co/guide/en/security/current/unusual-child-process-of-dns-exe.html
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_dns_susp_child_process.yml
author: Tim Rauch, Elastic (idea), Huntrule Team
date: 2022-09-27
modified: 2023-02-05
tags:
  - attack.persistence
  - attack.initial-access
  - attack.t1133
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    ParentImage|endswith: \dns.exe
  filter:
    Image|endswith: \conhost.exe
  condition: selection and not filter
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: a4e3d776-f12e-42c2-8510-9e6ed1f43ec3
    type: derived

What it detects

This rule flags process creation events where dns.exe spawns a child process that does not match the expected conhost.exe exception. Unexpected child processes from dns.exe can indicate compromised host activity, including exploitation workflows that rely on launching additional binaries. It relies on Windows process creation telemetry, matching the parent image by name and observing the spawned child process.

Known false positives

  • Unknown

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