User account created without expected attributes defined
Id | dc99e38c-f4e9-4837-94d7-353ac0b01a77 |
Rulename | User account created without expected attributes defined |
Description | This query looks for accounts being created that do not have attributes populated that are commonly populated in the tenant. Attackers may attempt to add accounts as a means of establishing persistant access to an environment, looking for anomalies in created accounts may help identify illegitimately created accounts. Created accounts should be investigated to ensure they were legitimated created. Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#accounts-not-following-naming-policies |
Severity | Low |
Tactics | Persistence |
Techniques | T1136.003 |
Required data connectors | AzureActiveDirectory |
Kind | Scheduled |
Query frequency | 1d |
Query period | 1d |
Trigger threshold | 0 |
Trigger operator | gt |
Source Uri | https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/Useraccountcreatedwithoutexpectedattributesdefined.yaml |
Version | 1.1.0 |
Arm template | dc99e38c-f4e9-4837-94d7-353ac0b01a77.json |
let threshold = 10;
let default_ad_attributes = dynamic(["LastDirSyncTime", "StsRefreshTokensValidFrom", "Included Updated Properties", "AccountEnabled", "Action Client Name", "SourceAnchor"]);
let addUsers = AuditLogs
| where OperationName =~ "Add user"
| where Result =~ "success"
| extend AccountProperties = TargetResources[0].modifiedProperties
| mv-expand AccountProperties
;
addUsers
| evaluate bag_unpack(AccountProperties) : (displayName:string, oldValue: string, newValue: string , TenantId : string, SourceSystem : string, TimeGenerated : datetime, ResourceId : string, OperationName : string, OperationVersion : string, Category : string, ResultType : string, ResultSignature : string, ResultDescription : string, DurationMs : long, CorrelationId : string, Resource : string, ResourceGroup : string, ResourceProvider : string, Identity : string, Level : string, Location : string, AdditionalDetails : dynamic, Id : string, InitiatedBy : dynamic, LoggedByService : string, Result : string, ResultReason : string, TargetResources : dynamic, AADTenantId : string, ActivityDisplayName : string, ActivityDateTime : datetime, AADOperationType : string, Type : string)
| extend displayName = column_ifexists("displayName", "Unknown Value")
| summarize count() by displayName, TenantId
| where displayName !in (default_ad_attributes)
| top threshold by count_ desc
| summarize make_set(displayName) by TenantId
| join kind=inner (
addUsers
| extend CreatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
| extend CreatingAadUserId = tostring(InitiatedBy.user.id)
| extend CreatingUserIPAddress = tostring(InitiatedBy.user.ipAddress)
| extend CreatedUserPrincipalName = tostring(TargetResources[0].userPrincipalName)
| extend PropName = tostring(AccountProperties.displayName))
on TenantId
| summarize makeset(PropName) by TimeGenerated, CorrelationId, CreatedUserPrincipalName, CreatingUserPrincipalName, CreatingAadUserId, CreatingUserIPAddress, tostring(set_displayName)
| extend missing_props = set_difference(todynamic(set_displayName), set_PropName)
| where array_length(missing_props) > 0
| join kind=innerunique (
AuditLogs
| where Result =~ "success"
| where OperationName =~ "Add user"
| extend CreatedUserPrincipalName = tostring(TargetResources[0].userPrincipalName))
on CorrelationId, CreatedUserPrincipalName
| extend ExpectedProperties = set_displayName
| project-away set_displayName, set_PropName
| extend InitiatingAccountName = tostring(split(CreatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(CreatingUserPrincipalName, "@")[1])
| extend TargetAccountName = tostring(split(CreatedUserPrincipalName, "@")[0]), TargetAccountUPNSuffix = tostring(split(CreatedUserPrincipalName, "@")[1])
triggerOperator: gt
metadata:
categories:
domains:
- Security - Others
support:
tier: Community
source:
kind: Community
author:
name: Microsoft Security Research
requiredDataConnectors:
- dataTypes:
- AuditLogs
connectorId: AzureActiveDirectory
queryPeriod: 1d
kind: Scheduled
description: |
'This query looks for accounts being created that do not have attributes populated that are commonly populated in the tenant.
Attackers may attempt to add accounts as a means of establishing persistant access to an environment, looking for anomalies in created accounts may help identify illegitimately created accounts.
Created accounts should be investigated to ensure they were legitimated created.
Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#accounts-not-following-naming-policies'
version: 1.1.0
query: |
let threshold = 10;
let default_ad_attributes = dynamic(["LastDirSyncTime", "StsRefreshTokensValidFrom", "Included Updated Properties", "AccountEnabled", "Action Client Name", "SourceAnchor"]);
let addUsers = AuditLogs
| where OperationName =~ "Add user"
| where Result =~ "success"
| extend AccountProperties = TargetResources[0].modifiedProperties
| mv-expand AccountProperties
;
addUsers
| evaluate bag_unpack(AccountProperties) : (displayName:string, oldValue: string, newValue: string , TenantId : string, SourceSystem : string, TimeGenerated : datetime, ResourceId : string, OperationName : string, OperationVersion : string, Category : string, ResultType : string, ResultSignature : string, ResultDescription : string, DurationMs : long, CorrelationId : string, Resource : string, ResourceGroup : string, ResourceProvider : string, Identity : string, Level : string, Location : string, AdditionalDetails : dynamic, Id : string, InitiatedBy : dynamic, LoggedByService : string, Result : string, ResultReason : string, TargetResources : dynamic, AADTenantId : string, ActivityDisplayName : string, ActivityDateTime : datetime, AADOperationType : string, Type : string)
| extend displayName = column_ifexists("displayName", "Unknown Value")
| summarize count() by displayName, TenantId
| where displayName !in (default_ad_attributes)
| top threshold by count_ desc
| summarize make_set(displayName) by TenantId
| join kind=inner (
addUsers
| extend CreatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
| extend CreatingAadUserId = tostring(InitiatedBy.user.id)
| extend CreatingUserIPAddress = tostring(InitiatedBy.user.ipAddress)
| extend CreatedUserPrincipalName = tostring(TargetResources[0].userPrincipalName)
| extend PropName = tostring(AccountProperties.displayName))
on TenantId
| summarize makeset(PropName) by TimeGenerated, CorrelationId, CreatedUserPrincipalName, CreatingUserPrincipalName, CreatingAadUserId, CreatingUserIPAddress, tostring(set_displayName)
| extend missing_props = set_difference(todynamic(set_displayName), set_PropName)
| where array_length(missing_props) > 0
| join kind=innerunique (
AuditLogs
| where Result =~ "success"
| where OperationName =~ "Add user"
| extend CreatedUserPrincipalName = tostring(TargetResources[0].userPrincipalName))
on CorrelationId, CreatedUserPrincipalName
| extend ExpectedProperties = set_displayName
| project-away set_displayName, set_PropName
| extend InitiatingAccountName = tostring(split(CreatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(CreatingUserPrincipalName, "@")[1])
| extend TargetAccountName = tostring(split(CreatedUserPrincipalName, "@")[0]), TargetAccountUPNSuffix = tostring(split(CreatedUserPrincipalName, "@")[1])
relevantTechniques:
- T1136.003
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/Useraccountcreatedwithoutexpectedattributesdefined.yaml
severity: Low
triggerThreshold: 0
name: User account created without expected attributes defined
tactics:
- Persistence
tags:
- AADSecOpsGuide
entityMappings:
- entityType: Account
fieldMappings:
- identifier: FullName
columnName: CreatingUserPrincipalName
- identifier: Name
columnName: InitiatingAccountName
- identifier: UPNSuffix
columnName: InitiatingAccountUPNSuffix
- entityType: Account
fieldMappings:
- identifier: AadUserId
columnName: CreatingAadUserId
- entityType: Account
fieldMappings:
- identifier: FullName
columnName: CreatedUserPrincipalName
- identifier: Name
columnName: TargetAccountName
- identifier: UPNSuffix
columnName: TargetAccountUPNSuffix
- entityType: IP
fieldMappings:
- identifier: Address
columnName: CreatingUserIPAddress
id: dc99e38c-f4e9-4837-94d7-353ac0b01a77
queryFrequency: 1d
{
"$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/dc99e38c-f4e9-4837-94d7-353ac0b01a77')]",
"kind": "Scheduled",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/dc99e38c-f4e9-4837-94d7-353ac0b01a77')]",
"properties": {
"alertRuleTemplateName": "dc99e38c-f4e9-4837-94d7-353ac0b01a77",
"customDetails": null,
"description": "'This query looks for accounts being created that do not have attributes populated that are commonly populated in the tenant.\n Attackers may attempt to add accounts as a means of establishing persistant access to an environment, looking for anomalies in created accounts may help identify illegitimately created accounts.\n Created accounts should be investigated to ensure they were legitimated created.\n Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#accounts-not-following-naming-policies'\n",
"displayName": "User account created without expected attributes defined",
"enabled": true,
"entityMappings": [
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "CreatingUserPrincipalName",
"identifier": "FullName"
},
{
"columnName": "InitiatingAccountName",
"identifier": "Name"
},
{
"columnName": "InitiatingAccountUPNSuffix",
"identifier": "UPNSuffix"
}
]
},
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "CreatingAadUserId",
"identifier": "AadUserId"
}
]
},
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "CreatedUserPrincipalName",
"identifier": "FullName"
},
{
"columnName": "TargetAccountName",
"identifier": "Name"
},
{
"columnName": "TargetAccountUPNSuffix",
"identifier": "UPNSuffix"
}
]
},
{
"entityType": "IP",
"fieldMappings": [
{
"columnName": "CreatingUserIPAddress",
"identifier": "Address"
}
]
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/Useraccountcreatedwithoutexpectedattributesdefined.yaml",
"query": "let threshold = 10;\nlet default_ad_attributes = dynamic([\"LastDirSyncTime\", \"StsRefreshTokensValidFrom\", \"Included Updated Properties\", \"AccountEnabled\", \"Action Client Name\", \"SourceAnchor\"]);\nlet addUsers = AuditLogs\n| where OperationName =~ \"Add user\"\n| where Result =~ \"success\"\n| extend AccountProperties = TargetResources[0].modifiedProperties\n| mv-expand AccountProperties\n;\naddUsers\n| evaluate bag_unpack(AccountProperties) : (displayName:string, oldValue: string, newValue: string , TenantId : string, SourceSystem : string, TimeGenerated : datetime, ResourceId : string, OperationName : string, OperationVersion : string, Category : string, ResultType : string, ResultSignature : string, ResultDescription : string, DurationMs : long, CorrelationId : string, Resource : string, ResourceGroup : string, ResourceProvider : string, Identity : string, Level : string, Location : string, AdditionalDetails : dynamic, Id : string, InitiatedBy : dynamic, LoggedByService : string, Result : string, ResultReason : string, TargetResources : dynamic, AADTenantId : string, ActivityDisplayName : string, ActivityDateTime : datetime, AADOperationType : string, Type : string)\n| extend displayName = column_ifexists(\"displayName\", \"Unknown Value\")\n| summarize count() by displayName, TenantId\n| where displayName !in (default_ad_attributes)\n| top threshold by count_ desc\n| summarize make_set(displayName) by TenantId\n| join kind=inner (\naddUsers\n| extend CreatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)\n| extend CreatingAadUserId = tostring(InitiatedBy.user.id)\n| extend CreatingUserIPAddress = tostring(InitiatedBy.user.ipAddress)\n| extend CreatedUserPrincipalName = tostring(TargetResources[0].userPrincipalName)\n| extend PropName = tostring(AccountProperties.displayName)) \non TenantId\n| summarize makeset(PropName) by TimeGenerated, CorrelationId, CreatedUserPrincipalName, CreatingUserPrincipalName, CreatingAadUserId, CreatingUserIPAddress, tostring(set_displayName)\n| extend missing_props = set_difference(todynamic(set_displayName), set_PropName)\n| where array_length(missing_props) > 0\n| join kind=innerunique (\nAuditLogs\n| where Result =~ \"success\"\n| where OperationName =~ \"Add user\"\n| extend CreatedUserPrincipalName = tostring(TargetResources[0].userPrincipalName)) \non CorrelationId, CreatedUserPrincipalName\n| extend ExpectedProperties = set_displayName\n| project-away set_displayName, set_PropName\n| extend InitiatingAccountName = tostring(split(CreatingUserPrincipalName, \"@\")[0]), InitiatingAccountUPNSuffix = tostring(split(CreatingUserPrincipalName, \"@\")[1])\n| extend TargetAccountName = tostring(split(CreatedUserPrincipalName, \"@\")[0]), TargetAccountUPNSuffix = tostring(split(CreatedUserPrincipalName, \"@\")[1])\n",
"queryFrequency": "P1D",
"queryPeriod": "P1D",
"severity": "Low",
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"Persistence"
],
"tags": [
"AADSecOpsGuide"
],
"techniques": [
"T1136"
],
"templateVersion": "1.1.0",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0
},
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
}
]
}