Anomalous Single Factor Signin

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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	1.0.4
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

requiredDataConnectors:
- dataTypes:
  - SigninLogs
  connectorId: AzureActiveDirectory
id: f7c3f5c8-71ea-49ff-b8b3-148f0e346291
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SigninLogs/AnomalousSingleFactorSignin.yaml
triggerThreshold: 0
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])  
severity: Low
entityMappings:
- fieldMappings:
  - columnName: UserPrincipalName
    identifier: FullName
  - columnName: Name
    identifier: Name
  - columnName: UPNSuffix
    identifier: UPNSuffix
  entityType: Account
- fieldMappings:
  - columnName: IPAddress
    identifier: Address
  entityType: IP
- fieldMappings:
  - columnName: AppId
    identifier: AppId
  - columnName: AppDisplayName
    identifier: Name
  entityType: CloudApplication
tags:
- AADSecOpsGuide
tactics:
- InitialAccess
version: 1.0.4
kind: Scheduled
metadata:
  categories:
    domains:
    - Security - Others
  support:
    tier: Community
  author:
    name: Pete Bryan
  source:
    kind: Community
relevantTechniques:
- T1078.004
name: Anomalous Single Factor Signin
triggerOperator: gt
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'  
queryPeriod: 7d

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": "1.0.4",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}