Azure Diagnostic settings removed from a resource

Severity: medium
Time window: 2h
Group by: CorrelationId, MonitoredResourcePath, OperationNameValue, _ResourceId
Author: KennethMLdk
Source: github.com/Azure/Azure-Sentinel

This query looks for diagnostic settings that are removed from a resource. This could indicate an attacker or malicious internal trying to evade detection before malicious act is performed. If the diagnostic settings are being deleted as part of a parent resource deletion, the event is ignores.

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1562.008` Impair Defenses: Disable or Modify Cloud Logs

Event coverage

Provider	Event
Azure-Microsoft.Insights	Microsoft.Insights/diagnosticSettings/delete

Rule body kusto

id: 6e95aef3-a1e0-4063-8e74-cd59aa59f245
name: Azure Diagnostic settings removed from a resource
description: |
  'This query looks for diagnostic settings that are removed from a resource.
  This could indicate an attacker or malicious internal trying to evade detection before malicious act is performed.
  If the diagnostic settings are being deleted as part of a parent resource deletion, the event is ignores.'
severity: Medium
requiredDataConnectors:
  - connectorId: AzureActivity
    dataTypes:
      - AzureActivity
queryFrequency: 1h
queryPeriod: 2h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - DefenseEvasion
relevantTechniques:
  - T1562.008
query: |
  AzureActivity
  | where OperationNameValue =~ "MICROSOFT.INSIGHTS/DIAGNOSTICSETTINGS/DELETE"
  | summarize
      TimeGenerated = arg_max(TimeGenerated, Properties),
      ActivityStatusValue = make_set(ActivityStatusValue, 5),
      take_any(Caller, CallerIpAddress, OperationName, ResourceGroup, Resource)
      by CorrelationId, _ResourceId, OperationNameValue
  | extend ResourceHierarchy = split(_ResourceId, "/")
  | extend MonitoredResourcePath = strcat_array(array_slice(ResourceHierarchy, 0, array_length(ResourceHierarchy)-5), "/")
  | join kind=leftanti (
      AzureActivity
      | where OperationNameValue !~ "MICROSOFT.INSIGHTS/DIAGNOSTICSETTINGS/DELETE" and OperationNameValue endswith "/DELETE" and ActivityStatusValue has_any ("Success", "Succeeded")
      | project _ResourceId
  ) on $left.MonitoredResourcePath == $right._ResourceId
  | extend
      Name = iif(Caller has "@", tostring(split(Caller, "@")[0]), ""),
      UPNSuffix = iif(Caller has "@", tostring(split(Caller, "@")[1]), ""),
      AadUserId = iif(Caller has "@", "", Caller)
  | project TimeGenerated, Caller, CallerIpAddress, OperationNameValue, OperationName, ActivityStatusValue, ResourceGroup, MonitoredResourcePath, Resource, Properties, Name, UPNSuffix, AadUserId, _ResourceId, CorrelationId
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: Caller
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: Account
    fieldMappings:
      - identifier: AadUserId
        columnName: AadUserId
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: CallerIpAddress
version: 1.0.3
kind: Scheduled
metadata:
    source:
        kind: Community
    author:
        name: KennethMLdk
    support:
        tier: Community
    categories:
        domains: [ "Security - Others", "Platform" ]

Stages and Predicates

Stage 1: `source`

AzureActivity

Stage 2: `where`

| where OperationNameValue =~ "MICROSOFT.INSIGHTS/DIAGNOSTICSETTINGS/DELETE"

Stage 3: `summarize`

| summarize
    TimeGenerated = arg_max(TimeGenerated, Properties),
    ActivityStatusValue = make_set(ActivityStatusValue, 5),
    take_any(Caller, CallerIpAddress, OperationName, ResourceGroup, Resource)
    by CorrelationId, _ResourceId, OperationNameValue

Stage 4: `extend`

| extend ResourceHierarchy = split(_ResourceId, "/")

Stage 5: `extend`

| extend MonitoredResourcePath = strcat_array(array_slice(ResourceHierarchy, 0, array_length(ResourceHierarchy)-5), "/")

Stage 6: `join` (negated)

| join kind=leftanti (
    AzureActivity
    | where OperationNameValue !~ "MICROSOFT.INSIGHTS/DIAGNOSTICSETTINGS/DELETE" and OperationNameValue endswith "/DELETE" and ActivityStatusValue has_any ("Success", "Succeeded")
    | project _ResourceId
) on $left.MonitoredResourcePath == $right._ResourceId

Stage 7: `extend`

| extend
    Name = iif(Caller has "@", tostring(split(Caller, "@")[0]), ""),
    UPNSuffix = iif(Caller has "@", tostring(split(Caller, "@")[1]), ""),
    AadUserId = iif(Caller has "@", "", Caller)

Stage 8: `project`

| project TimeGenerated, Caller, CallerIpAddress, OperationNameValue, OperationName, ActivityStatusValue, ResourceGroup, MonitoredResourcePath, Resource, Properties, Name, UPNSuffix, AadUserId, _ResourceId, CorrelationId

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`ActivityStatusValue`	match	`Success`, `Succeeded`
`OperationNameValue`	ends_with	`/DELETE`
`OperationNameValue`	ne	`MICROSOFT.INSIGHTS/DIAGNOSTICSETTINGS/DELETE`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`OperationNameValue`	eq	`MICROSOFT.INSIGHTS/DIAGNOSTICSETTINGS/DELETE`

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field	Source
`AadUserId`	`project`
`ActivityStatusValue`	`project`
`Caller`	`project`
`CallerIpAddress`	`project`
`CorrelationId`	`project`
`MonitoredResourcePath`	`project`
`Name`	`project`
`OperationName`	`project`
`OperationNameValue`	`project`
`Properties`	`project`
`Resource`	`project`
`ResourceGroup`	`project`
`TimeGenerated`	`project`
`UPNSuffix`	`project`
`_ResourceId`	`project`

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`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
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`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

Azure Diagnostic settings removed from a resource

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Stage 1: `source`

Stage 2: `where`

Stage 3: `summarize`

Stage 4: `extend`

Stage 5: `extend`

Stage 6: `join` (negated)

Stage 7: `extend`

Stage 8: `project`

Exclusions

Indicators

Output fields

Keyboard shortcuts

Search operators

Azure Diagnostic settings removed from a resource

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: summarize

Stage 4: extend

Stage 5: extend

Stage 6: join (negated)

Stage 7: extend

Stage 8: project

Exclusions

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `summarize`

Stage 4: `extend`

Stage 5: `extend`

Stage 6: `join` (negated)

Stage 7: `extend`

Stage 8: `project`