Guest Users Invited to Tenant by New Inviters
Id | 572e75ef-5147-49d9-9d65-13f2ed1e3a86 |
Rulename | Guest Users Invited to Tenant by New Inviters |
Description | Detects when a Guest User is added by a user account that has not been seen adding a guest in the previous 14 days. Monitoring guest accounts and the access they are provided is important to detect potential account abuse. Accounts added should be investigated to ensure the activity was legitimate. Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#monitoring-for-failed-unusual-sign-ins |
Severity | Medium |
Tactics | Persistence |
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/GuestUsersInvitedtoTenantbyNewInviters.yaml |
Version | 1.1.1 |
Arm template | 572e75ef-5147-49d9-9d65-13f2ed1e3a86.json |
let inviting_users = (AuditLogs
| where TimeGenerated between(ago(14d)..ago(1d))
| where OperationName =~ "Invite external user"
| where Result =~ "success"
| extend InitiatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
| where isnotempty(InitiatingUserPrincipalName)
| summarize by InitiatingUserPrincipalName);
AuditLogs
| where TimeGenerated > ago(1d)
| where OperationName =~ "Invite external user"
| where Result =~ "success"
| extend InitiatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
| extend InitiatingAadUserId = tostring(InitiatedBy.user.id)
| extend InitiatingIPAddress = tostring(InitiatedBy.user.ipAddress)
| where isnotempty(InitiatingUserPrincipalName) and InitiatingUserPrincipalName !in (inviting_users)
| extend TargetUserPrincipalName = tostring(TargetResources[0].userPrincipalName)
| extend TargetAadUserId = tostring(TargetResources[0].id)
| extend invitingUser = InitiatingUserPrincipalName, invitedUserPrincipalName = TargetUserPrincipalName
| extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, "@")[1])
| extend TargetAccountName = tostring(split(TargetUserPrincipalName, "@")[0]), TargetAccountUPNSuffix = tostring(split(TargetUserPrincipalName, "@")[1])
| project-reorder TimeGenerated, OperationName, Result, TargetUserPrincipalName, TargetAadUserId, InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingIPAddress
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/GuestUsersInvitedtoTenantbyNewInviters.yaml
metadata:
categories:
domains:
- Security - Others
- Identity
author:
name: Microsoft Security Research
source:
kind: Community
support:
tier: Community
id: 572e75ef-5147-49d9-9d65-13f2ed1e3a86
query: |
let inviting_users = (AuditLogs
| where TimeGenerated between(ago(14d)..ago(1d))
| where OperationName =~ "Invite external user"
| where Result =~ "success"
| extend InitiatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
| where isnotempty(InitiatingUserPrincipalName)
| summarize by InitiatingUserPrincipalName);
AuditLogs
| where TimeGenerated > ago(1d)
| where OperationName =~ "Invite external user"
| where Result =~ "success"
| extend InitiatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
| extend InitiatingAadUserId = tostring(InitiatedBy.user.id)
| extend InitiatingIPAddress = tostring(InitiatedBy.user.ipAddress)
| where isnotempty(InitiatingUserPrincipalName) and InitiatingUserPrincipalName !in (inviting_users)
| extend TargetUserPrincipalName = tostring(TargetResources[0].userPrincipalName)
| extend TargetAadUserId = tostring(TargetResources[0].id)
| extend invitingUser = InitiatingUserPrincipalName, invitedUserPrincipalName = TargetUserPrincipalName
| extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, "@")[1])
| extend TargetAccountName = tostring(split(TargetUserPrincipalName, "@")[0]), TargetAccountUPNSuffix = tostring(split(TargetUserPrincipalName, "@")[1])
| project-reorder TimeGenerated, OperationName, Result, TargetUserPrincipalName, TargetAadUserId, InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingIPAddress
tags:
- AADSecOpsGuide
description: |
'Detects when a Guest User is added by a user account that has not been seen adding a guest in the previous 14 days.
Monitoring guest accounts and the access they are provided is important to detect potential account abuse.
Accounts added should be investigated to ensure the activity was legitimate.
Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#monitoring-for-failed-unusual-sign-ins'
name: Guest Users Invited to Tenant by New Inviters
relevantTechniques:
- T1078.004
entityMappings:
- entityType: Account
fieldMappings:
- identifier: FullName
columnName: InitiatingUserPrincipalName
- identifier: Name
columnName: InitiatingAccountName
- identifier: UPNSuffix
columnName: InitiatingAccountUPNSuffix
- entityType: Account
fieldMappings:
- identifier: FullName
columnName: TargetUserPrincipalName
- identifier: Name
columnName: TargetAccountName
- identifier: UPNSuffix
columnName: TargetAccountUPNSuffix
- entityType: Account
fieldMappings:
- identifier: AadUserId
columnName: InitiatingAadUserId
- entityType: Account
fieldMappings:
- identifier: AadUserId
columnName: TargetAadUserId
- entityType: IP
fieldMappings:
- identifier: Address
columnName: InitiatingIPAddress
triggerThreshold: 0
severity: Medium
requiredDataConnectors:
- dataTypes:
- AuditLogs
connectorId: AzureActiveDirectory
queryFrequency: 1d
queryPeriod: 14d
version: 1.1.1
kind: Scheduled
tactics:
- Persistence
triggerOperator: gt
{
"$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/572e75ef-5147-49d9-9d65-13f2ed1e3a86')]",
"kind": "Scheduled",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/572e75ef-5147-49d9-9d65-13f2ed1e3a86')]",
"properties": {
"alertRuleTemplateName": "572e75ef-5147-49d9-9d65-13f2ed1e3a86",
"customDetails": null,
"description": "'Detects when a Guest User is added by a user account that has not been seen adding a guest in the previous 14 days.\n Monitoring guest accounts and the access they are provided is important to detect potential account abuse.\n Accounts added should be investigated to ensure the activity was legitimate.\n Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#monitoring-for-failed-unusual-sign-ins'\n",
"displayName": "Guest Users Invited to Tenant by New Inviters",
"enabled": true,
"entityMappings": [
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "InitiatingUserPrincipalName",
"identifier": "FullName"
},
{
"columnName": "InitiatingAccountName",
"identifier": "Name"
},
{
"columnName": "InitiatingAccountUPNSuffix",
"identifier": "UPNSuffix"
}
]
},
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "TargetUserPrincipalName",
"identifier": "FullName"
},
{
"columnName": "TargetAccountName",
"identifier": "Name"
},
{
"columnName": "TargetAccountUPNSuffix",
"identifier": "UPNSuffix"
}
]
},
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "InitiatingAadUserId",
"identifier": "AadUserId"
}
]
},
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "TargetAadUserId",
"identifier": "AadUserId"
}
]
},
{
"entityType": "IP",
"fieldMappings": [
{
"columnName": "InitiatingIPAddress",
"identifier": "Address"
}
]
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/GuestUsersInvitedtoTenantbyNewInviters.yaml",
"query": "let inviting_users = (AuditLogs\n | where TimeGenerated between(ago(14d)..ago(1d))\n | where OperationName =~ \"Invite external user\"\n | where Result =~ \"success\"\n | extend InitiatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)\n | where isnotempty(InitiatingUserPrincipalName)\n | summarize by InitiatingUserPrincipalName);\n AuditLogs\n | where TimeGenerated > ago(1d)\n | where OperationName =~ \"Invite external user\"\n | where Result =~ \"success\"\n | extend InitiatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)\n | extend InitiatingAadUserId = tostring(InitiatedBy.user.id)\n | extend InitiatingIPAddress = tostring(InitiatedBy.user.ipAddress)\n | where isnotempty(InitiatingUserPrincipalName) and InitiatingUserPrincipalName !in (inviting_users)\n | extend TargetUserPrincipalName = tostring(TargetResources[0].userPrincipalName)\n | extend TargetAadUserId = tostring(TargetResources[0].id)\n | extend invitingUser = InitiatingUserPrincipalName, invitedUserPrincipalName = TargetUserPrincipalName\n | extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, \"@\")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, \"@\")[1])\n | extend TargetAccountName = tostring(split(TargetUserPrincipalName, \"@\")[0]), TargetAccountUPNSuffix = tostring(split(TargetUserPrincipalName, \"@\")[1])\n | project-reorder TimeGenerated, OperationName, Result, TargetUserPrincipalName, TargetAadUserId, InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingIPAddress\n",
"queryFrequency": "P1D",
"queryPeriod": "P14D",
"severity": "Medium",
"subTechniques": [
"T1078.004"
],
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"Persistence"
],
"tags": [
"AADSecOpsGuide"
],
"techniques": [
"T1078"
],
"templateVersion": "1.1.1",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0
},
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
}
]
}