Anomalous Single Factor Signin | Microsoft Sentinel Analytic Rules

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Id	f7c3f5c8-71ea-49ff-b8b3-148f0e346291
Rulename	Anomalous Single Factor Signin
Description	Detects successful signins using single factor authentication where the device, location, and ASN are abnormal. Single factor authentications pose an opportunity to access compromised accounts, investigate these for anomalous occurrencess. Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-devices#non-compliant-device-sign-in
Severity	Low
Tactics	InitialAccess
Techniques	T1078.004
Required data connectors	AzureActiveDirectory
Kind	Scheduled
Query frequency	1d
Query period	7d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SigninLogs/AnomalousSingleFactorSignin.yaml
Version	1.0.6
Arm template	f7c3f5c8-71ea-49ff-b8b3-148f0e346291.json

KQL

let known_locations = (SigninLogs
  | where TimeGenerated between(ago(7d)..ago(1d))
  | where ResultType == 0
  | extend LocationDetail = strcat(Location, "-", LocationDetails.state)
  | summarize by LocationDetail);
let known_asn = (SigninLogs
  | where TimeGenerated between(ago(7d)..ago(1d))
  | where ResultType == 0
  | summarize by AutonomousSystemNumber);
SigninLogs
| where TimeGenerated > ago(1d)
| where ResultType == 0
| where isempty(DeviceDetail.deviceId)
| where AuthenticationRequirement == "singleFactorAuthentication"
| extend LocationParsed = parse_json(LocationDetails), DeviceParsed = parse_json(DeviceDetail)
| extend City = tostring(LocationParsed.city), State = tostring(LocationParsed.state)
| extend LocationDetail = strcat(Location, "-", State)
| extend DeviceId = tostring(DeviceParsed.deviceId), DeviceName=tostring(DeviceParsed.displayName), OS=tostring(DeviceParsed.operatingSystem), Browser=tostring(DeviceParsed.browser)
| where AutonomousSystemNumber !in (known_asn) and LocationDetail !in (known_locations)
| project TimeGenerated, Type, UserId, UserDisplayName, UserPrincipalName, IPAddress, Location, State, City, ResultType, ResultDescription, AppId, AppDisplayName, AuthenticationRequirement, ConditionalAccessStatus, ResourceDisplayName, ClientAppUsed, Identity, HomeTenantId, ResourceTenantId, Status, UserAgent, DeviceId, DeviceName, OS, Browser, MfaDetail
| extend Name = tostring(split(UserPrincipalName,'@',0)[0]), UPNSuffix = tostring(split(UserPrincipalName,'@',1)[0])

YAML

name: Anomalous Single Factor Signin
triggerOperator: gt
query: |
  let known_locations = (SigninLogs
    | where TimeGenerated between(ago(7d)..ago(1d))
    | where ResultType == 0
    | extend LocationDetail = strcat(Location, "-", LocationDetails.state)
    | summarize by LocationDetail);
  let known_asn = (SigninLogs
    | where TimeGenerated between(ago(7d)..ago(1d))
    | where ResultType == 0
    | summarize by AutonomousSystemNumber);
  SigninLogs
  | where TimeGenerated > ago(1d)
  | where ResultType == 0
  | where isempty(DeviceDetail.deviceId)
  | where AuthenticationRequirement == "singleFactorAuthentication"
  | extend LocationParsed = parse_json(LocationDetails), DeviceParsed = parse_json(DeviceDetail)
  | extend City = tostring(LocationParsed.city), State = tostring(LocationParsed.state)
  | extend LocationDetail = strcat(Location, "-", State)
  | extend DeviceId = tostring(DeviceParsed.deviceId), DeviceName=tostring(DeviceParsed.displayName), OS=tostring(DeviceParsed.operatingSystem), Browser=tostring(DeviceParsed.browser)
  | where AutonomousSystemNumber !in (known_asn) and LocationDetail !in (known_locations)
  | project TimeGenerated, Type, UserId, UserDisplayName, UserPrincipalName, IPAddress, Location, State, City, ResultType, ResultDescription, AppId, AppDisplayName, AuthenticationRequirement, ConditionalAccessStatus, ResourceDisplayName, ClientAppUsed, Identity, HomeTenantId, ResourceTenantId, Status, UserAgent, DeviceId, DeviceName, OS, Browser, MfaDetail
  | extend Name = tostring(split(UserPrincipalName,'@',0)[0]), UPNSuffix = tostring(split(UserPrincipalName,'@',1)[0])
queryFrequency: 1d
description: |
  'Detects successful signins using single factor authentication where the device, location, and ASN are abnormal.
   Single factor authentications pose an opportunity to access compromised accounts, investigate these for anomalous occurrencess.
   Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-devices#non-compliant-device-sign-in'
id: f7c3f5c8-71ea-49ff-b8b3-148f0e346291
triggerThreshold: 0
queryPeriod: 7d
version: 1.0.6
kind: Scheduled
relevantTechniques:
- T1078.004
tags:
- AADSecOpsGuide
severity: Low
requiredDataConnectors:
- connectorId: AzureActiveDirectory
  dataTypes:
  - SigninLogs
metadata:
  categories:
    domains:
    - Security - Others
  support:
    tier: Community
  author:
    name: Pete Bryan
  source:
    kind: Community
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SigninLogs/AnomalousSingleFactorSignin.yaml
tactics:
- InitialAccess
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: UserPrincipalName
  - identifier: Name
    columnName: Name
  - identifier: UPNSuffix
    columnName: UPNSuffix
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: IPAddress
  entityType: IP
- fieldMappings:
  - identifier: AppId
    columnName: AppId
  - identifier: Name
    columnName: AppDisplayName
  entityType: CloudApplication

ARM

{
  "$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/f7c3f5c8-71ea-49ff-b8b3-148f0e346291')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/f7c3f5c8-71ea-49ff-b8b3-148f0e346291')]",
      "properties": {
        "alertRuleTemplateName": "f7c3f5c8-71ea-49ff-b8b3-148f0e346291",
        "customDetails": null,
        "description": "'Detects successful signins using single factor authentication where the device, location, and ASN are abnormal.\n Single factor authentications pose an opportunity to access compromised accounts, investigate these for anomalous occurrencess.\n Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-devices#non-compliant-device-sign-in'\n",
        "displayName": "Anomalous Single Factor Signin",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "UserPrincipalName",
                "identifier": "FullName"
              },
              {
                "columnName": "Name",
                "identifier": "Name"
              },
              {
                "columnName": "UPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPAddress",
                "identifier": "Address"
              }
            ]
          },
          {
            "entityType": "CloudApplication",
            "fieldMappings": [
              {
                "columnName": "AppId",
                "identifier": "AppId"
              },
              {
                "columnName": "AppDisplayName",
                "identifier": "Name"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SigninLogs/AnomalousSingleFactorSignin.yaml",
        "query": "let known_locations = (SigninLogs\n  | where TimeGenerated between(ago(7d)..ago(1d))\n  | where ResultType == 0\n  | extend LocationDetail = strcat(Location, \"-\", LocationDetails.state)\n  | summarize by LocationDetail);\nlet known_asn = (SigninLogs\n  | where TimeGenerated between(ago(7d)..ago(1d))\n  | where ResultType == 0\n  | summarize by AutonomousSystemNumber);\nSigninLogs\n| where TimeGenerated > ago(1d)\n| where ResultType == 0\n| where isempty(DeviceDetail.deviceId)\n| where AuthenticationRequirement == \"singleFactorAuthentication\"\n| extend LocationParsed = parse_json(LocationDetails), DeviceParsed = parse_json(DeviceDetail)\n| extend City = tostring(LocationParsed.city), State = tostring(LocationParsed.state)\n| extend LocationDetail = strcat(Location, \"-\", State)\n| extend DeviceId = tostring(DeviceParsed.deviceId), DeviceName=tostring(DeviceParsed.displayName), OS=tostring(DeviceParsed.operatingSystem), Browser=tostring(DeviceParsed.browser)\n| where AutonomousSystemNumber !in (known_asn) and LocationDetail !in (known_locations)\n| project TimeGenerated, Type, UserId, UserDisplayName, UserPrincipalName, IPAddress, Location, State, City, ResultType, ResultDescription, AppId, AppDisplayName, AuthenticationRequirement, ConditionalAccessStatus, ResourceDisplayName, ClientAppUsed, Identity, HomeTenantId, ResourceTenantId, Status, UserAgent, DeviceId, DeviceName, OS, Browser, MfaDetail\n| extend Name = tostring(split(UserPrincipalName,'@',0)[0]), UPNSuffix = tostring(split(UserPrincipalName,'@',1)[0])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P7D",
        "severity": "Low",
        "subTechniques": [
          "T1078.004"
        ],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "tags": [
          "AADSecOpsGuide"
        ],
        "techniques": [
          "T1078"
        ],
        "templateVersion": "1.0.6",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}