Conditional Access Policy Modified by New User
| Id | 25a7f951-54b7-4cf5-9862-ebc04306c590 |
| Rulename | 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 |
| Tactics | DefenseEvasion |
| Techniques | T1078.004 |
| Required data connectors | AzureActiveDirectory |
| Kind | Scheduled |
| Query frequency | 1d |
| Query period | 14d |
| Trigger threshold | 0 |
| Trigger operator | gt |
| Source Uri | https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/ConditionalAccessPolicyModifiedbyNewUser.yaml |
| Version | 1.1.1 |
| Arm template | 25a7f951-54b7-4cf5-9862-ebc04306c590.json |
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
name: Conditional Access Policy Modified by New User
version: 1.1.1
severity: Medium
relevantTechniques:
- T1078.004
metadata:
author:
name: Microsoft Security Research
support:
tier: Community
categories:
domains:
- Security - Others
source:
kind: Community
entityMappings:
- fieldMappings:
- identifier: FullName
columnName: InitiatingUserPrincipalName
- identifier: Name
columnName: InitiatingAccountName
- identifier: UPNSuffix
columnName: InitiatingAccountUPNSuffix
entityType: Account
- fieldMappings:
- identifier: AadUserId
columnName: InitiatingAadUserId
entityType: Account
- fieldMappings:
- identifier: Address
columnName: InitiatingIPAddress
entityType: IP
- fieldMappings:
- identifier: AppId
columnName: InitiatingAppId
- identifier: Name
columnName: InitiatingAppName
entityType: CloudApplication
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
tactics:
- DefenseEvasion
triggerOperator: gt
id: 25a7f951-54b7-4cf5-9862-ebc04306c590
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'
queryFrequency: 1d
tags:
- AADSecOpsGuide
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/ConditionalAccessPolicyModifiedbyNewUser.yaml
triggerThreshold: 0
kind: Scheduled
queryPeriod: 14d
requiredDataConnectors:
- connectorId: AzureActiveDirectory
dataTypes:
- AuditLogs
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"workspace": {
"type": "String"
}
},
"resources": [
{
"apiVersion": "2023-02-01-preview",
"id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/25a7f951-54b7-4cf5-9862-ebc04306c590')]",
"kind": "Scheduled",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/25a7f951-54b7-4cf5-9862-ebc04306c590')]",
"properties": {
"alertRuleTemplateName": "25a7f951-54b7-4cf5-9862-ebc04306c590",
"customDetails": null,
"description": "'Detects a Conditional Access Policy being modified by a user who has not modified a policy in the last 14 days.\n A threat actor may try to modify policies to weaken the security controls in place.\n Investigate any change to ensure they are approved.\n Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-infrastructure#conditional-access'\n",
"displayName": "Conditional Access Policy Modified by New User",
"enabled": true,
"entityMappings": [
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "InitiatingUserPrincipalName",
"identifier": "FullName"
},
{
"columnName": "InitiatingAccountName",
"identifier": "Name"
},
{
"columnName": "InitiatingAccountUPNSuffix",
"identifier": "UPNSuffix"
}
]
},
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "InitiatingAadUserId",
"identifier": "AadUserId"
}
]
},
{
"entityType": "IP",
"fieldMappings": [
{
"columnName": "InitiatingIPAddress",
"identifier": "Address"
}
]
},
{
"entityType": "CloudApplication",
"fieldMappings": [
{
"columnName": "InitiatingAppId",
"identifier": "AppId"
},
{
"columnName": "InitiatingAppName",
"identifier": "Name"
}
]
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/ConditionalAccessPolicyModifiedbyNewUser.yaml",
"query": "let known_users = (AuditLogs\n | where TimeGenerated between(ago(14d)..ago(1d))\n | where OperationName has \"conditional access policy\"\n | where Result =~ \"success\"\n | extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)\n | summarize by InitiatingUserPrincipalName);\n AuditLogs\n | where TimeGenerated > ago(1d)\n | where OperationName has \"conditional access policy\"\n | where Result =~ \"success\"\n | extend InitiatingAppName = tostring(InitiatedBy.app.displayName)\n | extend InitiatingAppId = tostring(InitiatedBy.app.appId)\n | extend InitiatingAppServicePrincipalId = tostring(InitiatedBy.app.servicePrincipalId)\n | extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)\n | extend InitiatingAadUserId = tostring(InitiatedBy.user.id)\n | extend InitiatingIPAddress = tostring(InitiatedBy.user.ipAddress)\n | extend CAPolicyName = tostring(TargetResources[0].displayName)\n | where InitiatingUserPrincipalName !in (known_users)\n | extend NewPolicyValues = TargetResources[0].modifiedProperties[0].newValue\n | extend OldPolicyValues = TargetResources[0].modifiedProperties[0].oldValue\n | extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, \"@\")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, \"@\")[1])\n | project-reorder TimeGenerated, OperationName, CAPolicyName, InitiatingAppId, InitiatingAppName, InitiatingAppServicePrincipalId, InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingIPAddress, NewPolicyValues, OldPolicyValues\n",
"queryFrequency": "P1D",
"queryPeriod": "P14D",
"severity": "Medium",
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"DefenseEvasion"
],
"tags": [
"AADSecOpsGuide"
],
"techniques": [
"T1078"
],
"templateVersion": "1.1.1",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0
},
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
}
]
}