Creating keys with encrypt policy without MFA

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Id	454133a7-5427-4a7c-bdc4-0adfa84dda16
Rulename	Creating keys with encrypt policy without MFA
Description	Detection of KMS keys where action kms:Encrypt is accessible for everyone (also outside of your organization). This is an idicator that your account is compromised and the attacker uses the encryption key to compromise another company.
Severity	Medium
Tactics	Impact
Techniques	T1485
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_CreationofEncryptKeysWithoutMFA.yaml
Version	1.0.2
Arm template	454133a7-5427-4a7c-bdc4-0adfa84dda16.json

KQL

let check_actions = AWSCloudTrail
| where (EventName == "CreateKey" or EventName == "PutKeyPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
| extend state=parse_json(parse_json(replace_string(tostring(parse_json(RequestParameters)['policy']),'\\"','"')).['Statement'])
| mv-expand state
| extend Action= tostring(parse_json(state.['Action'][0])), Effect=tostring(parse_json(state.['Effect'])),
         Principal=tostring(parse_json(state.['Principal']))
| where (Action == "kms:Encrypt" or Action == "kms:*") and (Effect == 'Allow') and (Principal has "*")
| distinct AwsEventId;
AWSCloudTrail
| where (EventName == "CreateKey" or EventName == "PutKeyPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
| 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]), "")
| join kind=inner (check_actions) on AwsEventId
| extend timestamp = TimeGenerated
| project-away AwsEventId1

YAML

triggerOperator: gt
queryFrequency: 1d
description: |
    'Detection of KMS keys where action kms:Encrypt is accessible for everyone (also outside of your organization). This is an idicator that your account is compromised and the attacker uses the encryption key to compromise another company.'
status: Available
kind: Scheduled
triggerThreshold: 0
requiredDataConnectors:
- connectorId: AWS
  dataTypes:
  - AWSCloudTrail
version: 1.0.2
queryPeriod: 1d
name: Creating keys with encrypt policy without MFA
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_CreationofEncryptKeysWithoutMFA.yaml
id: 454133a7-5427-4a7c-bdc4-0adfa84dda16
tactics:
- Impact
relevantTechniques:
- T1485
severity: Medium
entityMappings:
- fieldMappings:
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  - identifier: CloudAppAccountId
    columnName: RecipientAccountId
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: SourceIpAddress
  entityType: IP
query: |
  let check_actions = AWSCloudTrail
  | where (EventName == "CreateKey" or EventName == "PutKeyPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
  | extend state=parse_json(parse_json(replace_string(tostring(parse_json(RequestParameters)['policy']),'\\"','"')).['Statement'])
  | mv-expand state
  | extend Action= tostring(parse_json(state.['Action'][0])), Effect=tostring(parse_json(state.['Effect'])),
           Principal=tostring(parse_json(state.['Principal']))
  | where (Action == "kms:Encrypt" or Action == "kms:*") and (Effect == 'Allow') and (Principal has "*")
  | distinct AwsEventId;
  AWSCloudTrail
  | where (EventName == "CreateKey" or EventName == "PutKeyPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
  | 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]), "")
  | join kind=inner (check_actions) on AwsEventId
  | extend timestamp = TimeGenerated
  | project-away AwsEventId1

ARM

{
  "$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/454133a7-5427-4a7c-bdc4-0adfa84dda16')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/454133a7-5427-4a7c-bdc4-0adfa84dda16')]",
      "properties": {
        "alertRuleTemplateName": "454133a7-5427-4a7c-bdc4-0adfa84dda16",
        "customDetails": null,
        "description": "'Detection of KMS keys where action kms:Encrypt is accessible for everyone (also outside of your organization). This is an idicator that your account is compromised and the attacker uses the encryption key to compromise another company.'\n",
        "displayName": "Creating keys with encrypt policy without MFA",
        "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_CreationofEncryptKeysWithoutMFA.yaml",
        "query": "let check_actions = AWSCloudTrail\n| where (EventName == \"CreateKey\" or EventName == \"PutKeyPolicy\") and isempty(ErrorCode) and isempty(ErrorMessage)\n| extend state=parse_json(parse_json(replace_string(tostring(parse_json(RequestParameters)['policy']),'\\\\\"','\"')).['Statement'])\n| mv-expand state\n| extend Action= tostring(parse_json(state.['Action'][0])), Effect=tostring(parse_json(state.['Effect'])),\n         Principal=tostring(parse_json(state.['Principal']))\n| where (Action == \"kms:Encrypt\" or Action == \"kms:*\") and (Effect == 'Allow') and (Principal has \"*\")\n| distinct AwsEventId;\nAWSCloudTrail\n| where (EventName == \"CreateKey\" or EventName == \"PutKeyPolicy\") and isempty(ErrorCode) and isempty(ErrorMessage)\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| join kind=inner (check_actions) on AwsEventId\n| extend timestamp = TimeGenerated\n| project-away AwsEventId1\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "techniques": [
          "T1485"
        ],
        "templateVersion": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}