SSM document is publicly exposed

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Id	75647b58-bcc8-4eb5-9658-46698d3fa153
Rulename	SSM document is publicly exposed
Description	Detected a SSM document that is publicly exposed, which could lead to sensitive information leakage to the public. Verify the object configurations.
Severity	Medium
Tactics	Discovery
Techniques	T1526
Required data connectors	AWS
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/Amazon Web Services/Analytic Rules/AWS_SSMPubliclyExposed.yaml
Version	1.0.1
Arm template	75647b58-bcc8-4eb5-9658-46698d3fa153.json

KQL

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

YAML

triggerThreshold: 0
requiredDataConnectors:
- connectorId: AWS
  dataTypes:
  - AWSCloudTrail
severity: Medium
queryFrequency: 1d
id: 75647b58-bcc8-4eb5-9658-46698d3fa153
relevantTechniques:
- T1526
queryPeriod: 1d
name: SSM document is publicly exposed
status: Available
kind: Scheduled
tactics:
- Discovery
triggerOperator: gt
version: 1.0.1
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
  - columnName: RecipientAccountId
    identifier: CloudAppAccountId
- entityType: IP
  fieldMappings:
  - columnName: SourceIpAddress
    identifier: Address
description: |
    'Detected a SSM document that is publicly exposed, which could lead to sensitive information leakage to the public. Verify the object configurations.'
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_SSMPubliclyExposed.yaml
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

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/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",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Discovery"
        ],
        "techniques": [
          "T1526"
        ],
        "templateVersion": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}