Suspicious overly permessive KMS key policy created

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Id	60dfc193-0f73-4279-b43c-110ade02b201
Rulename	Suspicious overly permessive KMS key policy created
Description	An overly permissive key policy was created, resulting in KMS keys where the kms:Encrypt action is accessible to everyone (even outside of the organization). This could mean that your account is compromised and that the attacker is using the encryption key to compromise other organizations.
Severity	High
Tactics	Impact
Techniques	T1486
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_OverlyPermessiveKMS.yaml
Version	1.0.0
Arm template	60dfc193-0f73-4279-b43c-110ade02b201.json

KQL

AWSCloudTrail
| where EventName in ("CreateKey","PutKeyPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
| extend Statement = parse_json(tostring((parse_json(RequestParameters).policy))).Statement
| mvexpand Statement
| extend Action = tostring(parse_json(Statement).Action), Effect = tostring(parse_json(Statement).Effect), Principal = iff(isnotempty(tostring(parse_json(Statement).Principal.AWS)),tostring(parse_json(Statement).Principal.AWS), tostring(parse_json(Statement).Principal))
| where Effect =~ "Allow" and (Action == "kms:Encrypt" or Action == "kms:*") and Principal == "*"
| extend UserIdentityUserName = iff(isnotempty(UserIdentityUserName), UserIdentityUserName, tostring(split(UserIdentityArn,'/')[-1]))
| extend timestamp = TimeGenerated, IPCustomEntity = SourceIpAddress, AccountCustomEntity = UserIdentityUserName

YAML

version: 1.0.0
status: Available
queryFrequency: 1d
requiredDataConnectors:
- connectorId: AWS
  dataTypes:
  - AWSCloudTrail
entityMappings:
- fieldMappings:
  - columnName: AccountCustomEntity
    identifier: FullName
  entityType: Account
- fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
  entityType: IP
kind: Scheduled
queryPeriod: 1d
severity: High
query: |
  AWSCloudTrail
  | where EventName in ("CreateKey","PutKeyPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
  | extend Statement = parse_json(tostring((parse_json(RequestParameters).policy))).Statement
  | mvexpand Statement
  | extend Action = tostring(parse_json(Statement).Action), Effect = tostring(parse_json(Statement).Effect), Principal = iff(isnotempty(tostring(parse_json(Statement).Principal.AWS)),tostring(parse_json(Statement).Principal.AWS), tostring(parse_json(Statement).Principal))
  | where Effect =~ "Allow" and (Action == "kms:Encrypt" or Action == "kms:*") and Principal == "*"
  | extend UserIdentityUserName = iff(isnotempty(UserIdentityUserName), UserIdentityUserName, tostring(split(UserIdentityArn,'/')[-1]))
  | extend timestamp = TimeGenerated, IPCustomEntity = SourceIpAddress, AccountCustomEntity = UserIdentityUserName  
triggerOperator: gt
id: 60dfc193-0f73-4279-b43c-110ade02b201
description: |
    'An overly permissive key policy was created, resulting in KMS keys where the kms:Encrypt action is accessible to everyone (even outside of the organization). This could mean that your account is compromised and that the attacker is using the encryption key to compromise other organizations.'
triggerThreshold: 0
name: Suspicious overly permessive KMS key policy created
relevantTechniques:
- T1486
tactics:
- Impact
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_OverlyPermessiveKMS.yaml

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/60dfc193-0f73-4279-b43c-110ade02b201')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/60dfc193-0f73-4279-b43c-110ade02b201')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01",
      "properties": {
        "displayName": "Suspicious overly permessive KMS key policy created",
        "description": "'An overly permissive key policy was created, resulting in KMS keys where the kms:Encrypt action is accessible to everyone (even outside of the organization). This could mean that your account is compromised and that the attacker is using the encryption key to compromise other organizations.'\n",
        "severity": "High",
        "enabled": true,
        "query": "AWSCloudTrail\n| where EventName in (\"CreateKey\",\"PutKeyPolicy\") and isempty(ErrorCode) and isempty(ErrorMessage)\n| extend Statement = parse_json(tostring((parse_json(RequestParameters).policy))).Statement\n| mvexpand Statement\n| extend Action = tostring(parse_json(Statement).Action), Effect = tostring(parse_json(Statement).Effect), Principal = iff(isnotempty(tostring(parse_json(Statement).Principal.AWS)),tostring(parse_json(Statement).Principal.AWS), tostring(parse_json(Statement).Principal))\n| where Effect =~ \"Allow\" and (Action == \"kms:Encrypt\" or Action == \"kms:*\") and Principal == \"*\"\n| extend UserIdentityUserName = iff(isnotempty(UserIdentityUserName), UserIdentityUserName, tostring(split(UserIdentityArn,'/')[-1]))\n| extend timestamp = TimeGenerated, IPCustomEntity = SourceIpAddress, AccountCustomEntity = UserIdentityUserName\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "techniques": [
          "T1486"
        ],
        "alertRuleTemplateName": "60dfc193-0f73-4279-b43c-110ade02b201",
        "customDetails": null,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "identifier": "FullName",
                "columnName": "AccountCustomEntity"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "identifier": "Address",
                "columnName": "IPCustomEntity"
              }
            ]
          }
        ],
        "status": "Available",
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_OverlyPermessiveKMS.yaml",
        "templateVersion": "1.0.0"
      }
    }
  ]
}