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-*
  • logs-azure*

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: 101 (version history)

Added (Elastic Stack release): 7.10.0

Last modified (Elastic Stack release): 8.6.0

Rule authors: Elastic

Rule license: Elastic License v2

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 by 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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Rule query

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event.dataset:azure.activitylogs and azure.activitylogs.operation_name
:"MICROSOFT.NETWORK/NETWORKWATCHERS/DELETE" and event.outcome:(Success
or success)

Threat mapping

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Framework: MITRE ATT&CKTM

Rule version history

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Version 101 (8.6.0 release)
  • Formatting only
Version 100 (8.5.0 release)
  • Formatting only
Version 8 (8.4.0 release)
  • Formatting only
Version 6 (8.1.0 release)
  • Formatting only
Version 5 (7.13.0 release)
  • Formatting only
Version 4 (7.12.0 release)
  • Updated query, changed from:

    event.dataset:azure.activitylogs and azure.activitylogs.operation_name
    :MICROSOFT.NETWORK/NETWORKWATCHERS/DELETE and event.outcome:(Success
    or success)
Version 3 (7.11.2 release)
  • Formatting only
Version 2 (7.11.0 release)
  • Updated query, changed from:

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