URL Added to Application from Unknown Domain

Severity: high
Time window: 2h
Author: Microsoft Security Research
Source: github.com/Azure/Azure-Sentinel

Detects a URL being added to an application where the domain is not one that is associated with the tenant. The query uses domains seen in sign in logs to determine if the domain is associated with the tenant. Applications associated with URLs not controlled by the organization can pose a security risk. Ref: https://learn.microsoft.com/en-gb/entra/architecture/security-operations-applications#application-configuration-changes

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1078.004` Valid Accounts: Cloud Accounts
Privilege Escalation	`T1078.004` Valid Accounts: Cloud Accounts

Event coverage

Provider	Event
Entra-AuditLogs	Update application

Rules detecting the same action

Other rules on this platform that filter on the same API call or operation.

Admin promotion after Role Management Application Permission Grant (Kusto)
Application ID URI Changed (Kusto)
Application Redirect URL Update (Kusto)
Changes to Application Logout URL (Kusto)
Changes to Application Ownership (Kusto)
full_access_as_app Granted To Application (Kusto)
Mail.Read Permissions Granted to Application (Kusto)
Microsoft Entra ID Role Management Permission Grant (Kusto)

Rule body kusto

id: 017e095a-94d8-430c-a047-e51a11fb737b
name: URL Added to Application from Unknown Domain
description: |
  'Detects a URL being added to an application where the domain is not one that is associated with the tenant.
    The query uses domains seen in sign in logs to determine if the domain is associated with the tenant.
    Applications associated with URLs not controlled by the organization can pose a security risk.
    Ref: https://learn.microsoft.com/en-gb/entra/architecture/security-operations-applications#application-configuration-changes'
severity: High
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - AuditLogs
queryFrequency: 2h
queryPeriod: 2h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Persistence
  - PrivilegeEscalation
relevantTechniques:
  - T1078.004
tags:
  - AADSecOpsGuide
query: |
  let domains =
    SigninLogs
    | where ResultType == 0
    | extend domain = split(UserPrincipalName, "@")[1]
    | extend domain = tostring(split(UserPrincipalName, "@")[1])
    | summarize by tolower(tostring(domain));
    AuditLogs
    | where Category =~ "ApplicationManagement"
    | where Result =~ "success"
    | where OperationName =~ 'Update Application'
    | mv-expand TargetResources
    | mv-expand TargetResources.modifiedProperties
    | where TargetResources_modifiedProperties.displayName =~ "AppAddress"
    | extend Key = tostring(TargetResources_modifiedProperties.displayName)
    | extend NewValue = TargetResources_modifiedProperties.newValue
    | extend OldValue = TargetResources_modifiedProperties.oldValue
    | where isnotempty(Key) and isnotempty(NewValue)
    | project-reorder Key, NewValue, OldValue
    | extend NewUrls = extract_all('"Address":([^,]*)', tostring(NewValue))
    | extend OldUrls = extract_all('"Address":([^,]*)', tostring(OldValue))
    | extend AddedUrls = set_difference(NewUrls, OldUrls)
    | where array_length(AddedUrls) > 0
    | extend UserAgent = iif(tostring(AdditionalDetails[0].key) == "User-Agent", tostring(AdditionalDetails[0].value), "")
    | extend InitiatingAppName = tostring(InitiatedBy.app.displayName)
    | 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 InitiatedBy = tostring(iff(isnotempty(InitiatingUserPrincipalName),InitiatingUserPrincipalName, InitiatingAppName))
    | extend AppDisplayName = tostring(TargetResources.displayName)
    | where isnotempty(AddedUrls)
    | mv-expand AddedUrls
    | extend AddedUrls = trim(@'"', tostring(AddedUrls))
    | extend Domain = extract("^(?:https?:\\/\\/)?(?:[^@\\/\\n]+@)?(?:www\\.)?([^:\\/?\\n]+)/", 1, replace_string(tolower(AddedUrls), '"', ""))
    | where isnotempty(Domain)
    | extend Domain = strcat(split(Domain, ".")[-2], ".", split(Domain, ".")[-1])
    | where Domain !in (domains)
    | project-reorder TimeGenerated, AppDisplayName, AddedUrls, InitiatedBy, UserAgent, InitiatingIPAddress
    | extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, "@")[1])
entityMappings:
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: AddedUrls
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: InitiatingAppName
      - identifier: AadUserId
        columnName: InitiatingAppServicePrincipalId
  - 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
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: `domains`

let domains = SigninLogs
  | where ResultType == 0
  | extend domain = split(UserPrincipalName, "@")[1]
  | extend domain = tostring(split(UserPrincipalName, "@")[1])
  | summarize by tolower(tostring(domain));

Stage 1: `source`

AuditLogs

Stage 2: `where`

| where Category =~ "ApplicationManagement"

Stage 3: `where`

| where Result =~ "success"

Stage 4: `where`

| where OperationName =~ 'Update Application'

Stage 5: `mv-expand`

| mv-expand TargetResources

Stage 6: `mv-expand`

| mv-expand TargetResources.modifiedProperties

Stage 7: `where`

| where TargetResources_modifiedProperties.displayName =~ "AppAddress"

Stage 8: `extend` (3 consecutive steps)

| extend Key = tostring(TargetResources_modifiedProperties.displayName)
| extend NewValue = TargetResources_modifiedProperties.newValue
| extend OldValue = TargetResources_modifiedProperties.oldValue

Stage 9: `where`

| where isnotempty(Key) and isnotempty(NewValue)

Stage 10: `project-reorder`

| project-reorder Key, NewValue, OldValue

Stage 11: `extend` (3 consecutive steps)

| extend NewUrls = extract_all('"Address":([^,]*)', tostring(NewValue))
| extend OldUrls = extract_all('"Address":([^,]*)', tostring(OldValue))
| extend AddedUrls = set_difference(NewUrls, OldUrls)

Stage 12: `where`

| where array_length(AddedUrls) > 0

Stage 13: `extend` (8 consecutive steps)

| extend UserAgent = iif(tostring(AdditionalDetails[0].key) == "User-Agent", tostring(AdditionalDetails[0].value), "")
| extend InitiatingAppName = tostring(InitiatedBy.app.displayName)
| 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 InitiatedBy = tostring(iff(isnotempty(InitiatingUserPrincipalName),InitiatingUserPrincipalName, InitiatingAppName))
| extend AppDisplayName = tostring(TargetResources.displayName)

Stage 14: `where`

| where isnotempty(AddedUrls)

Stage 15: `mv-expand`

| mv-expand AddedUrls

Stage 16: `extend`

| extend AddedUrls = trim(@'"', tostring(AddedUrls))

Stage 17: `extend`

| extend Domain = extract("^(?:https?:\\/\\/)?(?:[^@\\/\\n]+@)?(?:www\\.)?([^:\\/?\\n]+)/", 1, replace_string(tolower(AddedUrls), '"', ""))

Stage 18: `where`

| where isnotempty(Domain)

Stage 19: `extend`

| extend Domain = strcat(split(Domain, ".")[-2], ".", split(Domain, ".")[-1])

Stage 20: `where`

| where Domain !in (domains)

References domains (defined above).

Stage 21: `project-reorder`

| project-reorder TimeGenerated, AppDisplayName, AddedUrls, InitiatedBy, UserAgent, InitiatingIPAddress

Stage 22: `extend`

| extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, "@")[1])

Exclusions

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

Field	Kind	Excluded values
`Domain`	eq	`domains`

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
`AddedUrls`	gt	`0` transforms: `array_length`
`AddedUrls`	is_not_null	(no value, null check)
`Category`	eq	`ApplicationManagement`
`Domain`	is_not_null	(no value, null check)
`Key`	is_not_null	(no value, null check)
`NewValue`	is_not_null	(no value, null check)
`OperationName`	eq	`Update Application`
`Result`	eq	`success`
`displayName`	eq	`AppAddress`

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
`Key`	`extend`
`NewValue`	`extend`
`OldValue`	`extend`
`NewUrls`	`extend`
`OldUrls`	`extend`
`AddedUrls`	`extend`
`UserAgent`	`extend`
`InitiatingAppName`	`extend`
`InitiatingAppServicePrincipalId`	`extend`
`InitiatingUserPrincipalName`	`extend`
`InitiatingAadUserId`	`extend`
`InitiatingIPAddress`	`extend`
`InitiatedBy`	`extend`
`AppDisplayName`	`extend`
`Domain`	`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)

URL Added to Application from Unknown Domain

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Let binding: `domains`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `mv-expand`

Stage 6: `mv-expand`

Stage 7: `where`

Stage 8: `extend` (3 consecutive steps)

Stage 9: `where`

Stage 10: `project-reorder`

Stage 11: `extend` (3 consecutive steps)

Stage 12: `where`

Stage 13: `extend` (8 consecutive steps)

Stage 14: `where`

Stage 15: `mv-expand`

Stage 16: `extend`

Stage 17: `extend`

Stage 18: `where`

Stage 19: `extend`

Stage 20: `where`

Stage 21: `project-reorder`

Stage 22: `extend`

Exclusions

Indicators

Output fields

Keyboard shortcuts

Search operators

URL Added to Application from Unknown Domain

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Let binding: domains

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: where

Stage 5: mv-expand

Stage 6: mv-expand

Stage 7: where

Stage 8: extend (3 consecutive steps)

Stage 9: where

Stage 10: project-reorder

Stage 11: extend (3 consecutive steps)

Stage 12: where

Stage 13: extend (8 consecutive steps)

Stage 14: where

Stage 15: mv-expand

Stage 16: extend

Stage 17: extend

Stage 18: where

Stage 19: extend

Stage 20: where

Stage 21: project-reorder

Stage 22: extend

Exclusions

Indicators

Output fields

Let binding: `domains`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `mv-expand`

Stage 6: `mv-expand`

Stage 7: `where`

Stage 8: `extend` (3 consecutive steps)

Stage 9: `where`

Stage 10: `project-reorder`

Stage 11: `extend` (3 consecutive steps)

Stage 12: `where`

Stage 13: `extend` (8 consecutive steps)

Stage 14: `where`

Stage 15: `mv-expand`

Stage 16: `extend`

Stage 17: `extend`

Stage 18: `where`

Stage 19: `extend`

Stage 20: `where`

Stage 21: `project-reorder`

Stage 22: `extend`