User Account Created Using Incorrect Naming Format
| Id | ee55dc85-d2da-48c1-a6c0-3eaee62a8d56 |
| Rulename | User Account Created Using Incorrect Naming Format |
| Description | This query looks for accounts being created where the name does not match a defined pattern. 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. The user_regex field in the query needs to be populated with the expected pattern for the environment before deployment. 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/UserAccountCreatedUsingIncorrectNamingFormat.yaml |
| Version | 1.1.0 |
| Arm template | ee55dc85-d2da-48c1-a6c0-3eaee62a8d56.json |
// Add the environments expected username format regex below before deploying
let user_regex = "";
AuditLogs
| where OperationName =~ "Add user"
| where Result =~ "success"
| extend userAgent = 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 AddedUser = tostring(TargetResources[0].userPrincipalName)
| where AddedUser matches regex user_regex
| extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, "@")[1])
| extend TargetAccountName = tostring(split(AddedUser, "@")[0]), TargetAccountUPNSuffix = tostring(split(AddedUser, "@")[1])
entityMappings:
- fieldMappings:
- columnName: InitiatingAppName
identifier: Name
- columnName: InitiatingAppServicePrincipalId
identifier: AadUserId
entityType: Account
- fieldMappings:
- columnName: InitiatingUserPrincipalName
identifier: FullName
- columnName: InitiatingAccountName
identifier: Name
- columnName: InitiatingAccountUPNSuffix
identifier: UPNSuffix
entityType: Account
- fieldMappings:
- columnName: InitiatingAadUserId
identifier: AadUserId
entityType: Account
- fieldMappings:
- columnName: AddedUser
identifier: FullName
- columnName: TargetAccountName
identifier: Name
- columnName: TargetAccountUPNSuffix
identifier: UPNSuffix
entityType: Account
- fieldMappings:
- columnName: InitiatingIPAddress
identifier: Address
entityType: IP
queryPeriod: 1d
metadata:
source:
kind: Community
support:
tier: Community
categories:
domains:
- Security - Others
author:
name: Microsoft Security Research
requiredDataConnectors:
- dataTypes:
- AuditLogs
connectorId: AzureActiveDirectory
triggerThreshold: 0
kind: Scheduled
relevantTechniques:
- T1136.003
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/UserAccountCreatedUsingIncorrectNamingFormat.yaml
name: User Account Created Using Incorrect Naming Format
query: |
// Add the environments expected username format regex below before deploying
let user_regex = "";
AuditLogs
| where OperationName =~ "Add user"
| where Result =~ "success"
| extend userAgent = 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 AddedUser = tostring(TargetResources[0].userPrincipalName)
| where AddedUser matches regex user_regex
| extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, "@")[1])
| extend TargetAccountName = tostring(split(AddedUser, "@")[0]), TargetAccountUPNSuffix = tostring(split(AddedUser, "@")[1])
tags:
- AADSecOpsGuide
version: 1.1.0
id: ee55dc85-d2da-48c1-a6c0-3eaee62a8d56
tactics:
- Persistence
queryFrequency: 1d
triggerOperator: gt
description: |
'This query looks for accounts being created where the name does not match a defined pattern.
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.
The user_regex field in the query needs to be populated with the expected pattern for the environment before deployment.
Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#accounts-not-following-naming-policies'
severity: Low
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"workspace": {
"type": "String"
}
},
"resources": [
{
"apiVersion": "2024-01-01-preview",
"id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/ee55dc85-d2da-48c1-a6c0-3eaee62a8d56')]",
"kind": "Scheduled",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/ee55dc85-d2da-48c1-a6c0-3eaee62a8d56')]",
"properties": {
"alertRuleTemplateName": "ee55dc85-d2da-48c1-a6c0-3eaee62a8d56",
"customDetails": null,
"description": "'This query looks for accounts being created where the name does not match a defined pattern.\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 The user_regex field in the query needs to be populated with the expected pattern for the environment before deployment.\n Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#accounts-not-following-naming-policies'\n",
"displayName": "User Account Created Using Incorrect Naming Format",
"enabled": true,
"entityMappings": [
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "InitiatingAppName",
"identifier": "Name"
},
{
"columnName": "InitiatingAppServicePrincipalId",
"identifier": "AadUserId"
}
]
},
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "InitiatingUserPrincipalName",
"identifier": "FullName"
},
{
"columnName": "InitiatingAccountName",
"identifier": "Name"
},
{
"columnName": "InitiatingAccountUPNSuffix",
"identifier": "UPNSuffix"
}
]
},
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "InitiatingAadUserId",
"identifier": "AadUserId"
}
]
},
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "AddedUser",
"identifier": "FullName"
},
{
"columnName": "TargetAccountName",
"identifier": "Name"
},
{
"columnName": "TargetAccountUPNSuffix",
"identifier": "UPNSuffix"
}
]
},
{
"entityType": "IP",
"fieldMappings": [
{
"columnName": "InitiatingIPAddress",
"identifier": "Address"
}
]
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/UserAccountCreatedUsingIncorrectNamingFormat.yaml",
"query": "// Add the environments expected username format regex below before deploying\nlet user_regex = \"\";\nAuditLogs\n| where OperationName =~ \"Add user\"\n| where Result =~ \"success\"\n| extend userAgent = tostring(AdditionalDetails[0].value)\n| extend InitiatingAppName = tostring(InitiatedBy.app.displayName)\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 InitiatedBy = tostring(iff(isnotempty(InitiatingUserPrincipalName),InitiatingUserPrincipalName, InitiatingAppName))\n| extend AddedUser = tostring(TargetResources[0].userPrincipalName)\n| where AddedUser matches regex user_regex\n| extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, \"@\")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, \"@\")[1])\n| extend TargetAccountName = tostring(split(AddedUser, \"@\")[0]), TargetAccountUPNSuffix = tostring(split(AddedUser, \"@\")[1])\n",
"queryFrequency": "P1D",
"queryPeriod": "P1D",
"severity": "Low",
"subTechniques": [
"T1136.003"
],
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"Persistence"
],
"tags": [
"AADSecOpsGuide"
],
"techniques": [
"T1136"
],
"templateVersion": "1.1.0",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0
},
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
}
]
}