Remote File Download via PowerShell

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Identifies powershell.exe being used to download an executable file from an untrusted remote destination.

Rule type: eql

Rule indices:

  • winlogbeat-*
  • logs-endpoint.events.*
  • logs-windows.*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References: None

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Command and Control

Version: 3

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

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sequence by host.id, process.entity_id with maxspan=30s
  [network where process.name : ("powershell.exe", "pwsh.exe", "powershell_ise.exe") and network.protocol == "dns" and
   not dns.question.name : ("localhost", "*.microsoft.com", "*.azureedge.net", "*.powershellgallery.com", "*.windowsupdate.com", "metadata.google.internal") and
   not user.domain : "NT AUTHORITY"]
    [file where process.name : "powershell.exe" and event.type == "creation" and file.extension : ("exe", "dll", "ps1", "bat") and
   not file.name : "__PSScriptPolicy*.ps1"]

Framework: MITRE ATT&CKTM