Azure Network Watcher Deletion

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Identifies the deletion of a Network Watcher in Azure. Network Watchers are used to monitor, diagnose, view metrics, and enable or disable logs for resources in an Azure virtual network. An adversary may delete a Network Watcher in an attempt to evade defenses.

Rule type: query

Rule indices:

  • filebeat-*

Severity: medium

Risk score: 47

Runs every: 5 minutes

Searches indices from: now-25m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Cloud
  • Azure
  • Continuous Monitoring
  • SecOps
  • Network Security

Version: 1

Added (Elastic Stack release): 7.10.0

Rule authors: Elastic

Rule license: Elastic License

Potential false positives

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Network Watcher deletions may be done by a system or network administrator. Verify whether the username, hostname, and/or resource name should be making changes in your environment. Network Watcher deletions from unfamiliar users or hosts should be investigated. If known behavior is causing false positives, it can be exempted from the rule.

Investigation guide

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The Azure Filebeat module must be enabled to use this rule.

Rule query

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event.dataset:azure.activitylogs and azure.activitylogs.operation_name
:MICROSOFT.NETWORK/NETWORKWATCHERS/DELETE and event.outcome:Success

Threat mapping

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Framework: MITRE ATT&CKTM