Scheduled Task Created by a Windows Script

[metadata]
creation_date = "2020/11/29"
integration = ["endpoint", "windows"]
maturity = "production"
updated_date = "2026/05/04"

[rule]
author = ["Elastic"]
description = """
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.
"""
false_positives = ["Legitimate scheduled tasks may be created during installation of new software."]
from = "now-9m"
index = [
    "winlogbeat-*",
    "logs-endpoint.events.registry-*",
    "logs-endpoint.events.library-*",
    "logs-windows.sysmon_operational-*",
    "endgame-*",
]
language = "eql"
license = "Elastic License v2"
name = "Scheduled Task Created by a Windows Script"
note = """## Triage and analysis

Decode the base64 encoded Tasks Actions registry value to investigate the task's configured action."""
risk_score = 47
rule_id = "689b9d57-e4d5-4357-ad17-9c334609d79a"
severity = "medium"
tags = [
    "Domain: Endpoint",
    "OS: Windows",
    "Use Case: Threat Detection",
    "Tactic: Persistence",
    "Tactic: Execution",
    "Data Source: Elastic Endgame",
    "Data Source: Elastic Defend",
    "Data Source: Sysmon",
    "Resources: Investigation Guide",
]
type = "eql"

query = '''
sequence by host.id with maxspan = 30s
  [any where host.os.type == "windows" and 
    (event.category : ("library", "driver") 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 host.os.type == "windows" and event.type == "change" and registry.value : "Actions" and
    registry.path : (
      "HKLM\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Schedule\\TaskCache\\Tasks\\*\\Actions",
      "\\REGISTRY\\MACHINE\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Schedule\\TaskCache\\Tasks\\*\\Actions"
  )]
'''

setup = """## Setup

This rule is designed for data generated by [Elastic Defend](https://www.elastic.co/security/endpoint-security), which provides native endpoint detection and response, along with event enrichments designed to work with our detection rules.

Setup instructions: https://ela.st/install-elastic-defend

### Additional data sources

This rule also supports the following third-party data sources. For setup instructions, refer to the links below:

- [Sysmon Event ID 7 - Image Loaded](https://ela.st/sysmon-event-7-setup)
- [Sysmon Registry Events](https://ela.st/sysmon-event-reg-setup)
"""


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1053"
name = "Scheduled Task/Job"
reference = "https://attack.mitre.org/techniques/T1053/"
[[rule.threat.technique.subtechnique]]
id = "T1053.005"
name = "Scheduled Task"
reference = "https://attack.mitre.org/techniques/T1053/005/"



[rule.threat.tactic]
id = "TA0003"
name = "Persistence"
reference = "https://attack.mitre.org/tactics/TA0003/"
[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1059"
name = "Command and Scripting Interpreter"
reference = "https://attack.mitre.org/techniques/T1059/"
[[rule.threat.technique.subtechnique]]
id = "T1059.001"
name = "PowerShell"
reference = "https://attack.mitre.org/techniques/T1059/001/"

[[rule.threat.technique.subtechnique]]
id = "T1059.005"
name = "Visual Basic"
reference = "https://attack.mitre.org/techniques/T1059/005/"



[rule.threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"