Rare application consent

Back


Id	83ba3057-9ea3-4759-bf6a-933f2e5bc7ee
Rulename	Rare application consent
Description	This will alert when the “Consent to application” operation occurs by a user that has not done this operation before or rarely does this. This could indicate that permissions to access the listed Azure App were provided to a malicious actor. Consent to application, Add service principal and Add OAuth2PermissionGrant should typically be rare events. This may help detect the Oauth2 attack that can be initiated by this publicly available tool - https://github.com/fireeye/PwnAuth For further information on AuditLogs please see https://docs.microsoft.com/azure/active-directory/reports-monitoring/reference-audit-activities.
Severity	Medium
Tactics	Persistence PrivilegeEscalation
Techniques	T1136 T1068
Required data connectors	AzureActiveDirectory
Kind	Scheduled
Query frequency	1d
Query period	7d
Trigger threshold	3
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/Analytic Rules/RareApplicationConsent.yaml
Version	1.1.5
Arm template	83ba3057-9ea3-4759-bf6a-933f2e5bc7ee.json

KQL

let current = 1d;
let auditLookback = 7d;
// Setting threshold to 3 as a default, change as needed.
// Any operation that has been initiated by a user or app more than 3 times in the past 7 days will be excluded
let threshold = 3;
// Gather initial data from lookback period, excluding current, adjust current to more than a single day if no results
let AuditTrail = AuditLogs | where TimeGenerated >= ago(auditLookback) and TimeGenerated < ago(current)
// 2 other operations that can be part of malicious activity in this situation are
// "Add OAuth2PermissionGrant" and "Add service principal", extend the filter below to capture these too
| where OperationName has "Consent to application"
| extend InitiatedBy = iff(isnotempty(tostring(InitiatedBy.user.userPrincipalName)),
          tostring(InitiatedBy.user.userPrincipalName), tostring(InitiatedBy.app.displayName))
| mv-apply TargetResource = TargetResources on 
  (
      where TargetResource.type =~ "ServicePrincipal"
      | extend TargetResourceName = tolower(tostring(TargetResource.displayName))
  )
| summarize max(TimeGenerated), OperationCount = count() by OperationName, InitiatedBy, TargetResourceName
// only including operations initiated by a user or app that is above the threshold so we produce only rare and has not occurred in last 7 days
| where OperationCount > threshold;
// Gather current period of audit data
let RecentConsent = AuditLogs | where TimeGenerated >= ago(current)
| where OperationName has "Consent to application"
| extend IpAddress = case(
              isnotempty(tostring(InitiatedBy.user.ipAddress)) and tostring(InitiatedBy.user.ipAddress) != 'null', tostring(InitiatedBy.user.ipAddress),
              isnotempty(tostring(InitiatedBy.app.ipAddress)) and tostring(InitiatedBy.app.ipAddress) != 'null', tostring(InitiatedBy.app.ipAddress),
              'Not Available')
| extend InitiatedBy = iff(isnotempty(tostring(InitiatedBy.user.userPrincipalName)),
                          tostring(InitiatedBy.user.userPrincipalName), tostring(InitiatedBy.app.displayName))
| mv-apply TargetResource = TargetResources on 
  (
      where TargetResource.type =~ "ServicePrincipal"
      | extend TargetResourceName = tolower(tostring(TargetResource.displayName)),
               props = TargetResource.modifiedProperties
  )
| parse props with * "ConsentType: " ConsentType "]" *
| mv-apply AdditionalDetail = AdditionalDetails on 
  (
      where AdditionalDetail.key =~ "User-Agent"
      | extend UserAgent = tostring(AdditionalDetail.value)
  )
| project TimeGenerated, InitiatedBy, IpAddress, TargetResourceName, Category, OperationName, ConsentType, UserAgent, CorrelationId, Type;
// Exclude previously seen audit activity for "Consent to application" that was seen in the lookback period
// First for rare InitiatedBy
let RareConsentBy = RecentConsent | join kind= leftanti AuditTrail on OperationName, InitiatedBy
| extend Reason = "Previously unseen user consenting";
// Second for rare TargetResourceName
let RareConsentApp = RecentConsent | join kind= leftanti AuditTrail on OperationName, TargetResourceName
| extend Reason = "Previously unseen app granted consent";
RareConsentBy | union RareConsentApp
| summarize Reason = make_set(Reason,100) by TimeGenerated, InitiatedBy, IpAddress, TargetResourceName, Category, OperationName, ConsentType, UserAgent, CorrelationId, Type
| extend timestamp = TimeGenerated, Name = tolower(tostring(split(InitiatedBy,'@',0)[0])), UPNSuffix = tolower(tostring(split(InitiatedBy,'@',1)[0]))

YAML

id: 83ba3057-9ea3-4759-bf6a-933f2e5bc7ee
tactics:
- Persistence
- PrivilegeEscalation
queryPeriod: 7d
triggerThreshold: 3
name: Rare application consent
query: |
  let current = 1d;
  let auditLookback = 7d;
  // Setting threshold to 3 as a default, change as needed.
  // Any operation that has been initiated by a user or app more than 3 times in the past 7 days will be excluded
  let threshold = 3;
  // Gather initial data from lookback period, excluding current, adjust current to more than a single day if no results
  let AuditTrail = AuditLogs | where TimeGenerated >= ago(auditLookback) and TimeGenerated < ago(current)
  // 2 other operations that can be part of malicious activity in this situation are
  // "Add OAuth2PermissionGrant" and "Add service principal", extend the filter below to capture these too
  | where OperationName has "Consent to application"
  | extend InitiatedBy = iff(isnotempty(tostring(InitiatedBy.user.userPrincipalName)),
            tostring(InitiatedBy.user.userPrincipalName), tostring(InitiatedBy.app.displayName))
  | mv-apply TargetResource = TargetResources on 
    (
        where TargetResource.type =~ "ServicePrincipal"
        | extend TargetResourceName = tolower(tostring(TargetResource.displayName))
    )
  | summarize max(TimeGenerated), OperationCount = count() by OperationName, InitiatedBy, TargetResourceName
  // only including operations initiated by a user or app that is above the threshold so we produce only rare and has not occurred in last 7 days
  | where OperationCount > threshold;
  // Gather current period of audit data
  let RecentConsent = AuditLogs | where TimeGenerated >= ago(current)
  | where OperationName has "Consent to application"
  | extend IpAddress = case(
                isnotempty(tostring(InitiatedBy.user.ipAddress)) and tostring(InitiatedBy.user.ipAddress) != 'null', tostring(InitiatedBy.user.ipAddress),
                isnotempty(tostring(InitiatedBy.app.ipAddress)) and tostring(InitiatedBy.app.ipAddress) != 'null', tostring(InitiatedBy.app.ipAddress),
                'Not Available')
  | extend InitiatedBy = iff(isnotempty(tostring(InitiatedBy.user.userPrincipalName)),
                            tostring(InitiatedBy.user.userPrincipalName), tostring(InitiatedBy.app.displayName))
  | mv-apply TargetResource = TargetResources on 
    (
        where TargetResource.type =~ "ServicePrincipal"
        | extend TargetResourceName = tolower(tostring(TargetResource.displayName)),
                 props = TargetResource.modifiedProperties
    )
  | parse props with * "ConsentType: " ConsentType "]" *
  | mv-apply AdditionalDetail = AdditionalDetails on 
    (
        where AdditionalDetail.key =~ "User-Agent"
        | extend UserAgent = tostring(AdditionalDetail.value)
    )
  | project TimeGenerated, InitiatedBy, IpAddress, TargetResourceName, Category, OperationName, ConsentType, UserAgent, CorrelationId, Type;
  // Exclude previously seen audit activity for "Consent to application" that was seen in the lookback period
  // First for rare InitiatedBy
  let RareConsentBy = RecentConsent | join kind= leftanti AuditTrail on OperationName, InitiatedBy
  | extend Reason = "Previously unseen user consenting";
  // Second for rare TargetResourceName
  let RareConsentApp = RecentConsent | join kind= leftanti AuditTrail on OperationName, TargetResourceName
  | extend Reason = "Previously unseen app granted consent";
  RareConsentBy | union RareConsentApp
  | summarize Reason = make_set(Reason,100) by TimeGenerated, InitiatedBy, IpAddress, TargetResourceName, Category, OperationName, ConsentType, UserAgent, CorrelationId, Type
  | extend timestamp = TimeGenerated, Name = tolower(tostring(split(InitiatedBy,'@',0)[0])), UPNSuffix = tolower(tostring(split(InitiatedBy,'@',1)[0]))  
severity: Medium
triggerOperator: gt
kind: Scheduled
relevantTechniques:
- T1136
- T1068
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/Analytic Rules/RareApplicationConsent.yaml
queryFrequency: 1d
requiredDataConnectors:
- connectorId: AzureActiveDirectory
  dataTypes:
  - AuditLogs
description: |
  'This will alert when the "Consent to application" operation occurs by a user that has not done this operation before or rarely does this.
  This could indicate that permissions to access the listed Azure App were provided to a malicious actor.
  Consent to application, Add service principal and Add OAuth2PermissionGrant should typically be rare events.
  This may help detect the Oauth2 attack that can be initiated by this publicly available tool - https://github.com/fireeye/PwnAuth
  For further information on AuditLogs please see https://docs.microsoft.com/azure/active-directory/reports-monitoring/reference-audit-activities.'  
status: Available
version: 1.1.5
entityMappings:
- fieldMappings:
  - columnName: InitiatedBy
    identifier: FullName
  - columnName: Name
    identifier: Name
  - columnName: UPNSuffix
    identifier: UPNSuffix
  entityType: Account
- fieldMappings:
  - columnName: TargetResourceName
    identifier: Name
  entityType: CloudApplication
- fieldMappings:
  - columnName: IpAddress
    identifier: Address
  entityType: IP

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/83ba3057-9ea3-4759-bf6a-933f2e5bc7ee')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/83ba3057-9ea3-4759-bf6a-933f2e5bc7ee')]",
      "properties": {
        "alertRuleTemplateName": "83ba3057-9ea3-4759-bf6a-933f2e5bc7ee",
        "customDetails": null,
        "description": "'This will alert when the \"Consent to application\" operation occurs by a user that has not done this operation before or rarely does this.\nThis could indicate that permissions to access the listed Azure App were provided to a malicious actor.\nConsent to application, Add service principal and Add OAuth2PermissionGrant should typically be rare events.\nThis may help detect the Oauth2 attack that can be initiated by this publicly available tool - https://github.com/fireeye/PwnAuth\nFor further information on AuditLogs please see https://docs.microsoft.com/azure/active-directory/reports-monitoring/reference-audit-activities.'\n",
        "displayName": "Rare application consent",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "InitiatedBy",
                "identifier": "FullName"
              },
              {
                "columnName": "Name",
                "identifier": "Name"
              },
              {
                "columnName": "UPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "CloudApplication",
            "fieldMappings": [
              {
                "columnName": "TargetResourceName",
                "identifier": "Name"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IpAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/Analytic Rules/RareApplicationConsent.yaml",
        "query": "let current = 1d;\nlet auditLookback = 7d;\n// Setting threshold to 3 as a default, change as needed.\n// Any operation that has been initiated by a user or app more than 3 times in the past 7 days will be excluded\nlet threshold = 3;\n// Gather initial data from lookback period, excluding current, adjust current to more than a single day if no results\nlet AuditTrail = AuditLogs | where TimeGenerated >= ago(auditLookback) and TimeGenerated < ago(current)\n// 2 other operations that can be part of malicious activity in this situation are\n// \"Add OAuth2PermissionGrant\" and \"Add service principal\", extend the filter below to capture these too\n| where OperationName has \"Consent to application\"\n| extend InitiatedBy = iff(isnotempty(tostring(InitiatedBy.user.userPrincipalName)),\n          tostring(InitiatedBy.user.userPrincipalName), tostring(InitiatedBy.app.displayName))\n| mv-apply TargetResource = TargetResources on \n  (\n      where TargetResource.type =~ \"ServicePrincipal\"\n      | extend TargetResourceName = tolower(tostring(TargetResource.displayName))\n  )\n| summarize max(TimeGenerated), OperationCount = count() by OperationName, InitiatedBy, TargetResourceName\n// only including operations initiated by a user or app that is above the threshold so we produce only rare and has not occurred in last 7 days\n| where OperationCount > threshold;\n// Gather current period of audit data\nlet RecentConsent = AuditLogs | where TimeGenerated >= ago(current)\n| where OperationName has \"Consent to application\"\n| extend IpAddress = case(\n              isnotempty(tostring(InitiatedBy.user.ipAddress)) and tostring(InitiatedBy.user.ipAddress) != 'null', tostring(InitiatedBy.user.ipAddress),\n              isnotempty(tostring(InitiatedBy.app.ipAddress)) and tostring(InitiatedBy.app.ipAddress) != 'null', tostring(InitiatedBy.app.ipAddress),\n              'Not Available')\n| extend InitiatedBy = iff(isnotempty(tostring(InitiatedBy.user.userPrincipalName)),\n                          tostring(InitiatedBy.user.userPrincipalName), tostring(InitiatedBy.app.displayName))\n| mv-apply TargetResource = TargetResources on \n  (\n      where TargetResource.type =~ \"ServicePrincipal\"\n      | extend TargetResourceName = tolower(tostring(TargetResource.displayName)),\n               props = TargetResource.modifiedProperties\n  )\n| parse props with * \"ConsentType: \" ConsentType \"]\" *\n| mv-apply AdditionalDetail = AdditionalDetails on \n  (\n      where AdditionalDetail.key =~ \"User-Agent\"\n      | extend UserAgent = tostring(AdditionalDetail.value)\n  )\n| project TimeGenerated, InitiatedBy, IpAddress, TargetResourceName, Category, OperationName, ConsentType, UserAgent, CorrelationId, Type;\n// Exclude previously seen audit activity for \"Consent to application\" that was seen in the lookback period\n// First for rare InitiatedBy\nlet RareConsentBy = RecentConsent | join kind= leftanti AuditTrail on OperationName, InitiatedBy\n| extend Reason = \"Previously unseen user consenting\";\n// Second for rare TargetResourceName\nlet RareConsentApp = RecentConsent | join kind= leftanti AuditTrail on OperationName, TargetResourceName\n| extend Reason = \"Previously unseen app granted consent\";\nRareConsentBy | union RareConsentApp\n| summarize Reason = make_set(Reason,100) by TimeGenerated, InitiatedBy, IpAddress, TargetResourceName, Category, OperationName, ConsentType, UserAgent, CorrelationId, Type\n| extend timestamp = TimeGenerated, Name = tolower(tostring(split(InitiatedBy,'@',0)[0])), UPNSuffix = tolower(tostring(split(InitiatedBy,'@',1)[0]))\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P7D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Persistence",
          "PrivilegeEscalation"
        ],
        "techniques": [
          "T1068",
          "T1136"
        ],
        "templateVersion": "1.1.5",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 3
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}