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Elastic Docs ›Elastic Security Solution [8.4] ›Detections and alerts ›Prebuilt rule reference

Scheduled Task Created by a Windows Script

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Scheduled Task Created by a Windows Script

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A scheduled task was created by a Windows script via cscript.exe, wscript.exe or powershell.exe. This can be abused by an adversary to establish persistence.

Rule type: eql

Rule indices:

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

Severity: medium

Risk score: 47

Runs every: 5 minutes

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

Maximum alerts per execution: 100

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Persistence

Version: 7 (version history)

Added (Elastic Stack release): 7.11.0

Last modified (Elastic Stack release): 8.4.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positives

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Legitimate scheduled tasks may be created during installation of new software.

Investigation guide

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## Triage and analysis

Decode the base64 encoded Tasks Actions registry value to investigate the task's configured action.

Rule query

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sequence by host.id with maxspan = 30s [any where (event.category ==
"library" or (event.category == "process" and event.action : "Image
loaded*")) and (dll.name : "taskschd.dll" or file.name :
"taskschd.dll") and process.name : ("cscript.exe", "wscript.exe",
"powershell.exe", "pwsh.exe", "powershell_ise.exe")] [registry where
registry.path : "HKLM\\SOFTWARE\\Microsoft\\Windows
NT\\CurrentVersion\\Schedule\\TaskCache\\Tasks\\*\\Actions"]

Threat mapping

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Framework: MITRE ATT&CKTM

Rule version history

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Version 7 (8.4.0 release)

  • Updated query, changed from:

    sequence by host.id with maxspan = 30s [library where dll.name :
"taskschd.dll" and process.name : ("cscript.exe", "wscript.exe",
"powershell.exe", "pwsh.exe", "powershell_ise.exe")] [registry where
registry.path : "HKLM\\SOFTWARE\\Microsoft\\Windows
NT\\CurrentVersion\\Schedule\\TaskCache\\Tasks\\*\\Actions"]
Version 5 (7.16.0 release)

  • Updated query, changed from:

    sequence by host.id with maxspan = 30s [library where dll.name :
"taskschd.dll" and process.name : ("cscript.exe", "wscript.exe",
"powershell.exe")] [registry where registry.path :
"HKLM\\SOFTWARE\\Microsoft\\Windows
NT\\CurrentVersion\\Schedule\\TaskCache\\Tasks\\*\\Actions"]
Version 3 (7.13.0 release)
  • Formatting only
Version 2 (7.12.0 release)

  • Updated query, changed from:

    sequence by host.id with maxspan = 30s [library where file.name :
"taskschd.dll" and process.name : ("cscript.exe", "wscript.exe",
"powershell.exe")] [registry where registry.path :
"HKLM\\SOFTWARE\\Microsoft\\Windows
NT\\CurrentVersion\\Schedule\\TaskCache\\Tasks\\*\\Actions"]
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