SSM document is publicly exposed

AWSCloudTrail
| where  EventName == "ModifyDocumentPermission" and isempty(ErrorCode) and isempty(ErrorMessage)
| where todynamic(parse_json(RequestParameters).["accountIdsToAdd"]) == '["all"]'
| extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
| extend UserName = tostring(split(UserIdentityArn, '/')[-1])
| extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
| extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
  AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")  
| project TimeGenerated, EventName, EventTypeName, UserIdentityAccountId, UserIdentityPrincipalid, UserAgent,UserIdentityUserName, SessionMfaAuthenticated, RecipientAccountId, AccountName, AccountUPNSuffix, SourceIpAddress, AWSRegion, EventSource, AdditionalEventData, RequestParameters, ResponseElements, UserIdentityArn
| extend timestamp = TimeGenerated

name: SSM document is publicly exposed
query: |
  AWSCloudTrail
  | where  EventName == "ModifyDocumentPermission" and isempty(ErrorCode) and isempty(ErrorMessage)
  | where todynamic(parse_json(RequestParameters).["accountIdsToAdd"]) == '["all"]'
  | extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
  | extend UserName = tostring(split(UserIdentityArn, '/')[-1])
  | extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
  | extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
    AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")  
  | project TimeGenerated, EventName, EventTypeName, UserIdentityAccountId, UserIdentityPrincipalid, UserAgent,UserIdentityUserName, SessionMfaAuthenticated, RecipientAccountId, AccountName, AccountUPNSuffix, SourceIpAddress, AWSRegion, EventSource, AdditionalEventData, RequestParameters, ResponseElements, UserIdentityArn
  | extend timestamp = TimeGenerated  
description: |
    'Detected a SSM document that is publicly exposed, which could lead to sensitive information leakage to the public. Verify the object configurations.'
tactics:
- Discovery
requiredDataConnectors:
- dataTypes:
  - AWSCloudTrail
  connectorId: AWS
queryPeriod: 1d
queryFrequency: 1d
status: Available
triggerThreshold: 0
id: 75647b58-bcc8-4eb5-9658-46698d3fa153
triggerOperator: gt
version: 1.0.1
relevantTechniques:
- T1526
severity: Medium
kind: Scheduled
entityMappings:
- entityType: Account
  fieldMappings:
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  - identifier: CloudAppAccountId
    columnName: RecipientAccountId
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: SourceIpAddress
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_SSMPubliclyExposed.yaml

{
  "$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/75647b58-bcc8-4eb5-9658-46698d3fa153')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/75647b58-bcc8-4eb5-9658-46698d3fa153')]",
      "properties": {
        "alertRuleTemplateName": "75647b58-bcc8-4eb5-9658-46698d3fa153",
        "customDetails": null,
        "description": "'Detected a SSM document that is publicly exposed, which could lead to sensitive information leakage to the public. Verify the object configurations.'\n",
        "displayName": "SSM document is publicly exposed",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              },
              {
                "columnName": "RecipientAccountId",
                "identifier": "CloudAppAccountId"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "SourceIpAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_SSMPubliclyExposed.yaml",
        "query": "AWSCloudTrail\n| where  EventName == \"ModifyDocumentPermission\" and isempty(ErrorCode) and isempty(ErrorMessage)\n| where todynamic(parse_json(RequestParameters).[\"accountIdsToAdd\"]) == '[\"all\"]'\n| extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)\n| extend UserName = tostring(split(UserIdentityArn, '/')[-1])\n| extend AccountName = case( UserIdentityPrincipalid == \"Anonymous\", \"Anonymous\", isempty(UserIdentityUserName), UserName, UserIdentityUserName)\n| extend AccountName = iif(AccountName contains \"@\", tostring(split(AccountName, '@', 0)[0]), AccountName),\n  AccountUPNSuffix = iif(AccountName contains \"@\", tostring(split(AccountName, '@', 1)[0]), \"\")  \n| project TimeGenerated, EventName, EventTypeName, UserIdentityAccountId, UserIdentityPrincipalid, UserAgent,UserIdentityUserName, SessionMfaAuthenticated, RecipientAccountId, AccountName, AccountUPNSuffix, SourceIpAddress, AWSRegion, EventSource, AdditionalEventData, RequestParameters, ResponseElements, UserIdentityArn\n| extend timestamp = TimeGenerated\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Discovery"
        ],
        "techniques": [
          "T1526"
        ],
        "templateVersion": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}