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.*
  • 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:

Tags:

  • Domain: Endpoint
  • OS: Windows
  • Use Case: Threat Detection
  • Tactic: Persistence

Version: 8

Rule authors:

  • Elastic

Rule license: Elastic License v2

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 : "*Microsoft*" 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",
           "\\Microsoft\\Windows\\UpdateOrchestrator\\UpdateAssistant",
           "\\IpamDnsProvisioning",
           "\\Microsoft\\Windows\\UpdateOrchestrator\\UpdateAssistantAllUsersRun",
           "\\Microsoft\\Windows\\UpdateOrchestrator\\UpdateAssistantCalendarRun",
           "\\Microsoft\\Windows\\UpdateOrchestrator\\UpdateAssistantWakeupRun",
           "\\Microsoft\\Windows\\.NET Framework\\.NET Framework NGEN v*",
           "\\Microsoft\\VisualStudio\\Updates\\BackgroundDownload") and
  not winlog.event_data.SubjectUserSid :  ("S-1-5-18", "S-1-5-19", "S-1-5-20")

Framework: MITRE ATT&CKTM