A scheduled task was updated

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Indicates the update of a scheduled task using Windows event logs. Adversaries can use these to establish persistence, by changing the configuration of a legit scheduled task. Some changes such as disabling or enabling a scheduled task are common and may may generate noise.

Rule type: eql

Rule indices:

  • winlogbeat-*
  • logs-system.*

Severity: low

Risk score: 21

Runs every: 5 minutes

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

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Persistence

Version: 2 (version history)

Added (Elastic Stack release): 8.5.0

Last modified (Elastic Stack release): 8.6.0

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.

Rule query

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iam where event.action == "scheduled-task-updated" and /* excluding
tasks created by the computer account */ not user.name : "*$" and
not winlog.event_data.TaskName :
("\\User_Feed_Synchronization-*", "\\OneDrive Reporting
Task-S-1-5-21*", "\\OneDrive Reporting Task-S-1-12-1-*",
"\\Hewlett-Packard\\HP Web Products Detection", "\\Hewlett-
Packard\\HPDeviceCheck")

Threat mapping

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Framework: MITRE ATT&CKTM

Rule version history

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Version 2 (8.6.0 release)
  • Updated query, changed from:

    iam where event.action == "scheduled-task-updated" and /* excluding
    tasks created by the computer account */ not user.name : "*$" and
    not winlog.event_data.TaskName :
    ("\\User_Feed_Synchronization-*", "\\OneDrive Reporting
    Task-S-1-5-21*", "\\Hewlett-Packard\\HP Web Products
    Detection", "\\Hewlett-Packard\\HPDeviceCheck")