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

queryPeriod: 1d
id: 454133a7-5427-4a7c-bdc4-0adfa84dda16
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_CreationofEncryptKeysWithoutMFA.yaml
triggerOperator: gt
triggerThreshold: 0
entityMappings:
- fieldMappings:
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  - identifier: CloudAppAccountId
    columnName: RecipientAccountId
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: SourceIpAddress
  entityType: IP
status: Available
kind: Scheduled
name: Creating keys with encrypt policy without MFA
relevantTechniques:
- T1485
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.'
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  
version: 1.0.2
tactics:
- Impact
requiredDataConnectors:
- dataTypes:
  - AWSCloudTrail
  connectorId: AWS
severity: Medium
queryFrequency: 1d

ARM