Conditional Access Policy Modified by New User

Severity: medium
Time window: 14d
Author: Microsoft Security Research
Source: github.com/Azure/Azure-Sentinel

Detects a Conditional Access Policy being modified by a user who has not modified a policy in the last 14 days. A threat actor may try to modify policies to weaken the security controls in place. Investigate any change to ensure they are approved. Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-infrastructure#conditional-access

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1078.004` Valid Accounts: Cloud Accounts

Event coverage

Provider	Event	Title
Entra-AuditLogs	_catch_all	Entra ID audit event (any operation)

Rule body kusto

id: 25a7f951-54b7-4cf5-9862-ebc04306c590
name: Conditional Access Policy Modified by New User
description: |
  'Detects a Conditional Access Policy being modified by a user who has not modified a policy in the last 14 days.
    A threat actor may try to modify policies to weaken the security controls in place.
    Investigate any change to ensure they are approved.
    Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-infrastructure#conditional-access'
severity: Medium
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - AuditLogs
queryFrequency: 1d
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - DefenseEvasion
relevantTechniques:
  - T1078.004
tags:
  - AADSecOpsGuide
query: |
  let known_users = (AuditLogs
    | where TimeGenerated between(ago(14d)..ago(1d))
    | where OperationName has "conditional access policy"
    | where Result =~ "success"
    | extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)
    | summarize by InitiatingUserPrincipalName);
    AuditLogs
    | where TimeGenerated > ago(1d)
    | where OperationName has "conditional access policy"
    | where Result =~ "success"
    | extend InitiatingAppName = tostring(InitiatedBy.app.displayName)
    | extend InitiatingAppId = tostring(InitiatedBy.app.appId)
    | extend InitiatingAppServicePrincipalId = tostring(InitiatedBy.app.servicePrincipalId)
    | extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)
    | extend InitiatingAadUserId = tostring(InitiatedBy.user.id)
    | extend InitiatingIPAddress = tostring(InitiatedBy.user.ipAddress)
    | extend CAPolicyName = tostring(TargetResources[0].displayName)
    | where InitiatingUserPrincipalName !in (known_users)
    | extend NewPolicyValues = TargetResources[0].modifiedProperties[0].newValue
    | extend OldPolicyValues = TargetResources[0].modifiedProperties[0].oldValue
    | extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, "@")[1])
    | project-reorder TimeGenerated, OperationName, CAPolicyName, InitiatingAppId, InitiatingAppName, InitiatingAppServicePrincipalId, InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingIPAddress, NewPolicyValues, OldPolicyValues
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: InitiatingUserPrincipalName
      - identifier: Name
        columnName: InitiatingAccountName
      - identifier: UPNSuffix
        columnName: InitiatingAccountUPNSuffix
  - entityType: Account
    fieldMappings:
      - identifier: AadUserId
        columnName: InitiatingAadUserId
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: InitiatingIPAddress
  - entityType: CloudApplication
    fieldMappings:
      - identifier: AppId
        columnName: InitiatingAppId
      - identifier: Name
        columnName: InitiatingAppName
version: 1.1.1
kind: Scheduled
metadata:
    source:
        kind: Community
    author:
        name: Microsoft Security Research
    support:
        tier: Community
    categories:
        domains: [ "Security - Others" ]

Stages and Predicates

Let binding: `known_users`

let known_users = (AuditLogs
  | where TimeGenerated between(ago(14d)..ago(1d))
  | where OperationName has "conditional access policy"
  | where Result =~ "success"
  | extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)
  | summarize by InitiatingUserPrincipalName);

Stage 1: `source`

AuditLogs

Stage 2: `where`

| where TimeGenerated > ago(1d)

Stage 3: `where`

| where OperationName has "conditional access policy"

Stage 4: `where`

| where Result =~ "success"

Stage 5: `extend` (7 consecutive steps)

| extend InitiatingAppName = tostring(InitiatedBy.app.displayName)
| extend InitiatingAppId = tostring(InitiatedBy.app.appId)
| extend InitiatingAppServicePrincipalId = tostring(InitiatedBy.app.servicePrincipalId)
| extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)
| extend InitiatingAadUserId = tostring(InitiatedBy.user.id)
| extend InitiatingIPAddress = tostring(InitiatedBy.user.ipAddress)
| extend CAPolicyName = tostring(TargetResources[0].displayName)

Stage 6: `where`

| where InitiatingUserPrincipalName !in (known_users)

References known_users (defined above).

Stage 7: `extend` (3 consecutive steps)

| extend NewPolicyValues = TargetResources[0].modifiedProperties[0].newValue
| extend OldPolicyValues = TargetResources[0].modifiedProperties[0].oldValue
| extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, "@")[1])

Stage 8: `project-reorder`

| project-reorder TimeGenerated, OperationName, CAPolicyName, InitiatingAppId, InitiatingAppName, InitiatingAppServicePrincipalId, InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingIPAddress, NewPolicyValues, OldPolicyValues

Exclusions

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

Field	Kind	Excluded values
`InitiatingUserPrincipalName`	eq	`known_users`

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
`OperationName`	match	`conditional access policy` transforms: `term`
`Result`	eq	`success`

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
`InitiatingAppName`	`extend`
`InitiatingAppId`	`extend`
`InitiatingAppServicePrincipalId`	`extend`
`InitiatingUserPrincipalName`	`extend`
`InitiatingAadUserId`	`extend`
`InitiatingIPAddress`	`extend`
`CAPolicyName`	`extend`
`NewPolicyValues`	`extend`
`OldPolicyValues`	`extend`
`InitiatingAccountName`	`extend`
`InitiatingAccountUPNSuffix`	`extend`

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`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)

Conditional Access Policy Modified by New User

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Let binding: `known_users`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `extend` (7 consecutive steps)

Stage 6: `where`

Stage 7: `extend` (3 consecutive steps)

Stage 8: `project-reorder`

Exclusions

Indicators

Output fields

Keyboard shortcuts

Search operators

Conditional Access Policy Modified by New User

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Let binding: known_users

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: where

Stage 5: extend (7 consecutive steps)

Stage 6: where

Stage 7: extend (3 consecutive steps)

Stage 8: project-reorder

Exclusions

Indicators

Output fields

Let binding: `known_users`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `extend` (7 consecutive steps)

Stage 6: `where`

Stage 7: `extend` (3 consecutive steps)

Stage 8: `project-reorder`