Mail.Read Permissions Granted to Application

Status: available
Severity: medium
Time window: 1d
Source: github.com/Azure/Azure-Sentinel

This query look for applications that have been granted (Delegated or App/Role) permissions to Read Mail (Permissions field has Mail.Read) and subsequently has been consented to. This can help identify applications that have been abused to gain access to mailboxes.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1098` Account Manipulation

Event coverage

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

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)
Microsoft Entra ID Role Management Permission Grant (Kusto)
Suspicious application consent for offline access (Kusto)

Rule body kusto

id: 2560515c-07d1-434e-87fb-ebe3af267760
name: Mail.Read Permissions Granted to Application
description: |
  'This query look for applications that have been granted (Delegated or App/Role) permissions to Read Mail (Permissions field has Mail.Read) and subsequently has been consented to. This can help identify applications that have been abused to gain access to mailboxes.'
severity: Medium
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - AuditLogs
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
status: Available
tactics:
  - Persistence
relevantTechniques:
  - T1098
tags:
  - Solorigate
  - NOBELIUM
query: |
  AuditLogs
  | where Category =~ "ApplicationManagement"
  | where ActivityDisplayName has_any ("Add delegated permission grant","Add app role assignment to service principal")  
  | where Result =~ "success"
  | where tostring(InitiatedBy.user.userPrincipalName) has "@" or tostring(InitiatedBy.app.displayName) has "@"
  | mv-apply TargetResource = TargetResources on 
    (
        where TargetResource.type =~ "ServicePrincipal" and array_length(TargetResource.modifiedProperties) > 0 and isnotnull(TargetResource.displayName)
        | extend props = TargetResource.modifiedProperties,
                 Type = tostring(TargetResource.type),
                 PermissionsAddedTo = tostring(TargetResource.displayName)
    )
  | mv-apply Property = props on 
    (
        where Property.displayName =~ "DelegatedPermissionGrant.Scope"
        | extend DisplayName = tostring(Property.displayName), Permissions = trim('"',tostring(Property.newValue))
    )
  | where Permissions has_any ("Mail.Read", "Mail.ReadWrite")
  | mv-apply AdditionalDetail = AdditionalDetails on 
    (
        where AdditionalDetail.key =~ "User-Agent"
        | extend InitiatingUserAgent = tostring(AdditionalDetail.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(iff(isnotempty(InitiatedBy.user.ipAddress), InitiatedBy.user.ipAddress, InitiatedBy.app.ipAddress))
  | project-away props, TargetResource, AdditionalDetail, Property
  | join kind=leftouter(
    AuditLogs
    | where ActivityDisplayName has "Consent to application"
    | mv-apply TargetResource = TargetResources on 
        (
            where TargetResource.type =~ "ServicePrincipal"
            | extend AppName = tostring(TargetResource.displayName),
                     AppId = tostring(TargetResource.id)
        )
  | project AppName, AppId, CorrelationId) on CorrelationId
  | project-away CorrelationId1
  | project-reorder TimeGenerated, OperationName, InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingAppName, InitiatingAppServicePrincipalId, InitiatingIpAddress, InitiatingUserAgent, PermissionsAddedTo, Permissions, AppName, AppId, CorrelationId
  | extend Name = tostring(split(InitiatingUserPrincipalName,'@',0)[0]), UPNSuffix = tostring(split(InitiatingUserPrincipalName,'@',1)[0])
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: InitiatingUserPrincipalName
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: Account
    fieldMappings:
      - identifier: AadUserId
        columnName: InitiatingAadUserId
  - entityType: Account
    fieldMappings:
      - identifier: AadUserId
        columnName: InitiatingAppServicePrincipalId
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: InitiatingIpAddress
version: 1.0.4
kind: Scheduled

Stages and Predicates

Stage 1: `source`

AuditLogs

Stage 2: `where`

| where Category =~ "ApplicationManagement"

Stage 3: `where`

| where ActivityDisplayName has_any ("Add delegated permission grant","Add app role assignment to service principal")

Stage 4: `where`

| where Result =~ "success"

Stage 5: `where`

| where tostring(InitiatedBy.user.userPrincipalName) has "@" or tostring(InitiatedBy.app.displayName) has "@"

Stage 6: `kusto:mv-apply`

| mv-apply TargetResource = TargetResources on 
  (
      where TargetResource.type =~ "ServicePrincipal" and array_length(TargetResource.modifiedProperties) > 0 and isnotnull(TargetResource.displayName)
      | extend props = TargetResource.modifiedProperties,
               Type = tostring(TargetResource.type),
               PermissionsAddedTo = tostring(TargetResource.displayName)
  )

Stage 7: `kusto:mv-apply`

| mv-apply Property = props on 
  (
      where Property.displayName =~ "DelegatedPermissionGrant.Scope"
      | extend DisplayName = tostring(Property.displayName), Permissions = trim('"',tostring(Property.newValue))
  )

Stage 8: `where`

| where Permissions has_any ("Mail.Read", "Mail.ReadWrite")

Stage 9: `kusto:mv-apply`

| mv-apply AdditionalDetail = AdditionalDetails on 
  (
      where AdditionalDetail.key =~ "User-Agent"
      | extend InitiatingUserAgent = tostring(AdditionalDetail.value)
  )

Stage 10: `extend` (5 consecutive steps)

| 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(iff(isnotempty(InitiatedBy.user.ipAddress), InitiatedBy.user.ipAddress, InitiatedBy.app.ipAddress))

Stage 11: `project-away`

| project-away props, TargetResource, AdditionalDetail, Property

Stage 12: `join`

| join kind=leftouter(
  AuditLogs
  | where ActivityDisplayName has "Consent to application"
  | mv-apply TargetResource = TargetResources on 
      (
          where TargetResource.type =~ "ServicePrincipal"
          | extend AppName = tostring(TargetResource.displayName),
                   AppId = tostring(TargetResource.id)
      )
| project AppName, AppId, CorrelationId) on CorrelationId

Stage 13: `project-away`

| project-away CorrelationId1

Stage 14: `project-reorder`

| project-reorder TimeGenerated, OperationName, InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingAppName, InitiatingAppServicePrincipalId, InitiatingIpAddress, InitiatingUserAgent, PermissionsAddedTo, Permissions, AppName, AppId, CorrelationId

Stage 15: `extend`

| extend Name = tostring(split(InitiatingUserPrincipalName,'@',0)[0]), UPNSuffix = tostring(split(InitiatingUserPrincipalName,'@',1)[0])

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
`ActivityDisplayName`	match	`Add app role assignment to service principal` `Add delegated permission grant` `Consent to application` transforms: `term`
`Category`	eq	`ApplicationManagement`
`Permissions`	match	`Mail.Read` `Mail.ReadWrite`
`Result`	eq	`success`
`displayName`	eq	`DelegatedPermissionGrant.Scope`
`displayName`	is_not_null	(no value, null check)
`displayName`	match	`@` transforms: `tostring`, `term`
`key`	eq	`User-Agent`
`modifiedProperties`	gt	`0` transforms: `array_length`
`type`	eq	`ServicePrincipal`
`userPrincipalName`	match	`@` transforms: `tostring`, `term`

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`
`InitiatingAppServicePrincipalId`	`extend`
`InitiatingUserPrincipalName`	`extend`
`InitiatingAadUserId`	`extend`
`InitiatingIpAddress`	`extend`
`Name`	`extend`
`UPNSuffix`	`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)

Mail.Read Permissions Granted to Application

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `where`

Stage 6: `kusto:mv-apply`

Stage 7: `kusto:mv-apply`

Stage 8: `where`

Stage 9: `kusto:mv-apply`

Stage 10: `extend` (5 consecutive steps)

Stage 11: `project-away`

Stage 12: `join`

Stage 13: `project-away`

Stage 14: `project-reorder`

Stage 15: `extend`

Indicators

Output fields

Keyboard shortcuts

Search operators

Mail.Read Permissions Granted to Application

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: where

Stage 5: where

Stage 6: kusto:mv-apply

Stage 7: kusto:mv-apply

Stage 8: where

Stage 9: kusto:mv-apply

Stage 10: extend (5 consecutive steps)

Stage 11: project-away

Stage 12: join

Stage 13: project-away

Stage 14: project-reorder

Stage 15: extend

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `where`

Stage 6: `kusto:mv-apply`

Stage 7: `kusto:mv-apply`

Stage 8: `where`

Stage 9: `kusto:mv-apply`

Stage 10: `extend` (5 consecutive steps)

Stage 11: `project-away`

Stage 12: `join`

Stage 13: `project-away`

Stage 14: `project-reorder`

Stage 15: `extend`