Detection rules › Kusto
Conditional Access - A Conditional Access user/group/role exclusion has changed
A Conditional Access user/group/role exclusion has changed in Azure AD.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1078 Valid Accounts, T1098 Account Manipulation |
| Stealth | T1078 Valid Accounts |
Event coverage
| Provider | Event |
|---|---|
| Entra-AuditLogs | Update conditional access policy |
Rule body kusto
id: 2ce7f00d-3b3c-41b9-ae9a-b79c19d2394e
name: Conditional Access - A Conditional Access user/group/role exclusion has changed
version: 1.0.1
kind: Scheduled
description: A Conditional Access user/group/role exclusion has changed in Azure AD.
severity: High
requiredDataConnectors:
- connectorId: AzureActiveDirectory
dataTypes:
- AuditLogs
queryFrequency: 5m
queryPeriod: 5m
triggerOperator: gt
triggerThreshold: 0
tactics:
- Persistence
- DefenseEvasion
- CredentialAccess
relevantTechniques:
- T1098
- T1078
query: |+
// A Conditional Access user/group/role exclusion has changed.
AuditLogs
| where OperationName in ("Update conditional access policy")
| extend excludeUsersOld = extractjson("$.conditions.users.excludeUsers", tostring(TargetResources[0].modifiedProperties[0].oldValue))
| extend excludeGroupsOld = extractjson("$.conditions.users.excludeGroups", tostring(TargetResources[0].modifiedProperties[0].oldValue))
| extend excludeRolesOld = extractjson("$.conditions.users.excludeRoles", tostring(TargetResources[0].modifiedProperties[0].oldValue))
| extend excludeUsersNew = extractjson("$.conditions.users.excludeUsers", tostring(TargetResources[0].modifiedProperties[0].newValue))
| extend excludeGroupsNew = extractjson("$.conditions.users.excludeGroups", tostring(TargetResources[0].modifiedProperties[0].newValue))
| extend excludeRolesNew = extractjson("$.conditions.users.excludeRoles", tostring(TargetResources[0].modifiedProperties[0].newValue))
| where excludeUsersOld != excludeUsersNew or excludeGroupsOld != excludeGroupsNew or excludeRolesOld != excludeRolesNew
| extend modifiedBy = tostring(InitiatedBy.user.userPrincipalName)
| extend accountName = tostring(split(modifiedBy, "@")[0])
| extend upnSuffix = tostring(split(modifiedBy, "@")[1])
| project TimeGenerated, OperationName, policy = TargetResources[0].displayName, modifiedBy, accountName, upnSuffix, result = Result,
excludeUsersOld, excludeUsersNew, excludeGroupsOld, excludeGroupsNew, excludeRolesOld, excludeRolesNew
| order by TimeGenerated desc
entityMappings:
- entityType: Account
fieldMappings:
- identifier: Name
columnName: accountName
- identifier: UPNSuffix
columnName: upnSuffix
suppressionEnabled: false
suppressionDuration: 5h
eventGroupingSettings:
aggregationKind: AlertPerResult
incidentConfiguration:
createIncident: true
groupingConfiguration:
enabled: false
reopenClosedIncident: false
lookbackDuration: PT1H
matchingMethod: AllEntities
groupByEntities: []
groupByAlertDetails: []
groupByCustomDetails: []
Stages and Predicates
Stage 1: source
AuditLogs
Stage 2: where
| where OperationName in ("Update conditional access policy")
Stage 3: extend (6 consecutive steps)
| extend excludeUsersOld = extractjson("$.conditions.users.excludeUsers", tostring(TargetResources[0].modifiedProperties[0].oldValue))
| extend excludeGroupsOld = extractjson("$.conditions.users.excludeGroups", tostring(TargetResources[0].modifiedProperties[0].oldValue))
| extend excludeRolesOld = extractjson("$.conditions.users.excludeRoles", tostring(TargetResources[0].modifiedProperties[0].oldValue))
| extend excludeUsersNew = extractjson("$.conditions.users.excludeUsers", tostring(TargetResources[0].modifiedProperties[0].newValue))
| extend excludeGroupsNew = extractjson("$.conditions.users.excludeGroups", tostring(TargetResources[0].modifiedProperties[0].newValue))
| extend excludeRolesNew = extractjson("$.conditions.users.excludeRoles", tostring(TargetResources[0].modifiedProperties[0].newValue))
Stage 4: where
| where excludeUsersOld != excludeUsersNew or excludeGroupsOld != excludeGroupsNew or excludeRolesOld != excludeRolesNew
Stage 5: extend (3 consecutive steps)
| extend modifiedBy = tostring(InitiatedBy.user.userPrincipalName)
| extend accountName = tostring(split(modifiedBy, "@")[0])
| extend upnSuffix = tostring(split(modifiedBy, "@")[1])
Stage 6: project
| project TimeGenerated, OperationName, policy = TargetResources[0].displayName, modifiedBy, accountName, upnSuffix, result = Result,
excludeUsersOld, excludeUsersNew, excludeGroupsOld, excludeGroupsNew, excludeRolesOld, excludeRolesNew
Stage 7: sort
| order by TimeGenerated desc
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 | in |
|
excludeGroupsOld | ne |
|
excludeRolesOld | ne |
|
excludeUsersOld | ne |
|
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 |
|---|---|
OperationName | project |
TimeGenerated | project |
accountName | project |
excludeGroupsNew | project |
excludeGroupsOld | project |
excludeRolesNew | project |
excludeRolesOld | project |
excludeUsersNew | project |
excludeUsersOld | project |
modifiedBy | project |
policy | project |
result | project |
upnSuffix | project |