Azure DevOps Retention Reduced

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Id	71d374e0-1cf8-4e50-aecd-ab6c519795c2
Rulename	Azure DevOps Retention Reduced
Description	AzureDevOps retains items such as run records and produced artifacts for a configurable amount of time. An attacker looking to reduce the footprint left by their malicious activity may look to reduce the retention time for artifacts and runs. This query will look for where retention has been reduced to the minimum level - 1, or reduced by more than half.
Severity	Low
Tactics	DefenseEvasion
Techniques	T1564
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/AzureDevOpsAuditing/Analytic Rules/ADORetentionReduced.yaml
Version	1.0.4
Arm template	71d374e0-1cf8-4e50-aecd-ab6c519795c2.json

KQL

AzureDevOpsAuditing
| where OperationName =~ "Pipelines.PipelineRetentionSettingChanged"
| where Data.SettingName in ("PurgeArtifacts", "PurgeRuns")
| where Data.NewValue == 1 or Data.NewValue < Data.OldValue/2
| project-reorder TimeGenerated, OperationName, ActorUPN, IpAddress, UserAgent, Data
| extend timestamp = TimeGenerated
| extend AccountName = tostring(split(ActorUPN, "@")[0]), AccountUPNSuffix = tostring(split(ActorUPN, "@")[1])

YAML

id: 71d374e0-1cf8-4e50-aecd-ab6c519795c2
tactics:
- DefenseEvasion
queryPeriod: 1d
triggerThreshold: 0
name: Azure DevOps Retention Reduced
query: |
  AzureDevOpsAuditing
  | where OperationName =~ "Pipelines.PipelineRetentionSettingChanged"
  | where Data.SettingName in ("PurgeArtifacts", "PurgeRuns")
  | where Data.NewValue == 1 or Data.NewValue < Data.OldValue/2
  | project-reorder TimeGenerated, OperationName, ActorUPN, IpAddress, UserAgent, Data
  | extend timestamp = TimeGenerated
  | extend AccountName = tostring(split(ActorUPN, "@")[0]), AccountUPNSuffix = tostring(split(ActorUPN, "@")[1])  
severity: Low
triggerOperator: gt
kind: Scheduled
relevantTechniques:
- T1564
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/AzureDevOpsAuditing/Analytic Rules/ADORetentionReduced.yaml
queryFrequency: 1d
requiredDataConnectors: []
description: |
  'AzureDevOps retains items such as run records and produced artifacts for a configurable amount of time. An attacker looking to reduce the footprint left by their malicious activity may look to reduce the retention time for artifacts and runs.
  This query will look for where retention has been reduced to the minimum level - 1, or reduced by more than half.'  
status: Available
version: 1.0.4
entityMappings:
- fieldMappings:
  - columnName: ActorUPN
    identifier: FullName
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
  entityType: Account
- 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/71d374e0-1cf8-4e50-aecd-ab6c519795c2')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/71d374e0-1cf8-4e50-aecd-ab6c519795c2')]",
      "properties": {
        "alertRuleTemplateName": "71d374e0-1cf8-4e50-aecd-ab6c519795c2",
        "customDetails": null,
        "description": "'AzureDevOps retains items such as run records and produced artifacts for a configurable amount of time. An attacker looking to reduce the footprint left by their malicious activity may look to reduce the retention time for artifacts and runs.\nThis query will look for where retention has been reduced to the minimum level - 1, or reduced by more than half.'\n",
        "displayName": "Azure DevOps Retention Reduced",
        "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/ADORetentionReduced.yaml",
        "query": "AzureDevOpsAuditing\n| where OperationName =~ \"Pipelines.PipelineRetentionSettingChanged\"\n| where Data.SettingName in (\"PurgeArtifacts\", \"PurgeRuns\")\n| where Data.NewValue == 1 or Data.NewValue < Data.OldValue/2\n| project-reorder TimeGenerated, OperationName, ActorUPN, IpAddress, UserAgent, Data\n| extend timestamp = TimeGenerated\n| extend AccountName = tostring(split(ActorUPN, \"@\")[0]), AccountUPNSuffix = tostring(split(ActorUPN, \"@\")[1])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Low",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion"
        ],
        "techniques": [
          "T1564"
        ],
        "templateVersion": "1.0.4",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}