Azure DevOps Service Connection Abuse

// How many greater than Service Connections you want to view per build/release
let ServiceConnectionThreshold = 4;
let BypassDefIds = datatable(DefId:string, Type:string, ProjectName:string)
[
//"103", "Release", "ProjectA",
//"42", "Release", "ProjectB",
//"122", "Build", "ProjectB"
];
AzureDevOpsAuditing
| where OperationName == "Library.ServiceConnectionExecuted"
| extend DefId = tostring(Data.DefinitionId), Type = tostring(Data.PlanType), ConnectionId = tostring(Data.ConnectionId)
| parse ScopeDisplayName with OrganizationName ' (Organization)'
| summarize CurrentCount = dcount(tostring(ConnectionId)), ConnectionNames = make_set(tostring(Data.ConnectionName)), StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)
  by OrganizationName, tostring(DefId), tostring(Type), ProjectId, ProjectName, ActorUPN, IpAddress
| where CurrentCount > ServiceConnectionThreshold
| join kind=anti BypassDefIds on $left.DefId==$right.DefId and $left.Type == $right.Type and $left.ProjectName == $right.ProjectName
| extend link = iif(
  Type == "Build", strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_build?definitionId=', DefId),
  strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_release?_a=releases&view=mine&definitionId=', DefId))
| extend timestamp = StartTime
| extend AccountName = tostring(split(ActorUPN, "@")[0]), AccountUPNSuffix = tostring(split(ActorUPN, "@")[1])

relevantTechniques:
- T1098
- T1496
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/AzureDevOpsAuditing/Analytic Rules/AzDOServiceConnectionUsage.yaml
triggerOperator: gt
kind: Scheduled
entityMappings:
- fieldMappings:
  - columnName: ActorUPN
    identifier: FullName
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
  entityType: Account
- fieldMappings:
  - columnName: IpAddress
    identifier: Address
  entityType: IP
requiredDataConnectors: []
queryPeriod: 14d
query: |
  // How many greater than Service Connections you want to view per build/release
  let ServiceConnectionThreshold = 4;
  let BypassDefIds = datatable(DefId:string, Type:string, ProjectName:string)
  [
  //"103", "Release", "ProjectA",
  //"42", "Release", "ProjectB",
  //"122", "Build", "ProjectB"
  ];
  AzureDevOpsAuditing
  | where OperationName == "Library.ServiceConnectionExecuted"
  | extend DefId = tostring(Data.DefinitionId), Type = tostring(Data.PlanType), ConnectionId = tostring(Data.ConnectionId)
  | parse ScopeDisplayName with OrganizationName ' (Organization)'
  | summarize CurrentCount = dcount(tostring(ConnectionId)), ConnectionNames = make_set(tostring(Data.ConnectionName)), StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)
    by OrganizationName, tostring(DefId), tostring(Type), ProjectId, ProjectName, ActorUPN, IpAddress
  | where CurrentCount > ServiceConnectionThreshold
  | join kind=anti BypassDefIds on $left.DefId==$right.DefId and $left.Type == $right.Type and $left.ProjectName == $right.ProjectName
  | extend link = iif(
    Type == "Build", strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_build?definitionId=', DefId),
    strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_release?_a=releases&view=mine&definitionId=', DefId))
  | extend timestamp = StartTime
  | extend AccountName = tostring(split(ActorUPN, "@")[0]), AccountUPNSuffix = tostring(split(ActorUPN, "@")[1])  
version: 1.0.4
description: |
  'Flags builds/releases that use a large number of service connections if they aren't manually in the allow list.
  This is to determine if someone is hijacking a build/release and adding many service connections in order to abuse
  or dump credentials from service connections.'  
tactics:
- Persistence
- Impact
severity: Medium
name: Azure DevOps Service Connection Abuse
queryFrequency: 1d
triggerThreshold: 0
status: Available
id: d564ff12-8f53-41b8-8649-44f76b37b99f

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/d564ff12-8f53-41b8-8649-44f76b37b99f')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/d564ff12-8f53-41b8-8649-44f76b37b99f')]",
      "properties": {
        "alertRuleTemplateName": "d564ff12-8f53-41b8-8649-44f76b37b99f",
        "customDetails": null,
        "description": "'Flags builds/releases that use a large number of service connections if they aren't manually in the allow list.\nThis is to determine if someone is hijacking a build/release and adding many service connections in order to abuse\nor dump credentials from service connections.'\n",
        "displayName": "Azure DevOps Service Connection Abuse",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "ActorUPN",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IpAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/AzureDevOpsAuditing/Analytic Rules/AzDOServiceConnectionUsage.yaml",
        "query": "// How many greater than Service Connections you want to view per build/release\nlet ServiceConnectionThreshold = 4;\nlet BypassDefIds = datatable(DefId:string, Type:string, ProjectName:string)\n[\n//\"103\", \"Release\", \"ProjectA\",\n//\"42\", \"Release\", \"ProjectB\",\n//\"122\", \"Build\", \"ProjectB\"\n];\nAzureDevOpsAuditing\n| where OperationName == \"Library.ServiceConnectionExecuted\"\n| extend DefId = tostring(Data.DefinitionId), Type = tostring(Data.PlanType), ConnectionId = tostring(Data.ConnectionId)\n| parse ScopeDisplayName with OrganizationName ' (Organization)'\n| summarize CurrentCount = dcount(tostring(ConnectionId)), ConnectionNames = make_set(tostring(Data.ConnectionName)), StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)\n  by OrganizationName, tostring(DefId), tostring(Type), ProjectId, ProjectName, ActorUPN, IpAddress\n| where CurrentCount > ServiceConnectionThreshold\n| join kind=anti BypassDefIds on $left.DefId==$right.DefId and $left.Type == $right.Type and $left.ProjectName == $right.ProjectName\n| extend link = iif(\n  Type == \"Build\", strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_build?definitionId=', DefId),\n  strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_release?_a=releases&view=mine&definitionId=', DefId))\n| extend timestamp = StartTime\n| extend AccountName = tostring(split(ActorUPN, \"@\")[0]), AccountUPNSuffix = tostring(split(ActorUPN, \"@\")[1])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P14D",
        "severity": "Medium",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact",
          "Persistence"
        ],
        "techniques": [
          "T1098",
          "T1496"
        ],
        "templateVersion": "1.0.4",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}