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AWSCloudTrail - Creation of CRUD KMS policy and then privilege escalation

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Id8e15998e-1e32-4b6d-abd1-e8482e8f3def
RulenameAWSCloudTrail - Creation of CRUD KMS policy and then privilege escalation
DescriptionIdentifies creation of IAM policies that grant permissions for broad KMS CRUD actions, followed by attachment activity to a principal. This sequence can be used to expand access to encryption keys or

disable protections and should be investigated as possible privilege escalation.
SeverityMedium
TacticsDefenseEvasion
PrivilegeEscalation
Persistence
TechniquesT1484
T1098.003
Required data connectorsAWS
KindScheduled
Query frequency1d
Query period1d
Trigger threshold0
Trigger operatorgt
Source Urihttps://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_CreatedCRUDKMSPolicytoPrivilegeEscalation.yaml
Version1.0.3
Arm template8e15998e-1e32-4b6d-abd1-e8482e8f3def.json
Deploy To Azure
let EventNameList = dynamic(["AttachUserPolicy","AttachRolePolicy","AttachGroupPolicy"]);
let createPolicy =  dynamic(["CreatePolicy", "CreatePolicyVersion"]);
let timeframe = 1d;
let lookback = 14d;
// Creating Master table with all the events to use with materialize for better performance
let EventInfo = AWSCloudTrail
| where TimeGenerated >= ago(lookback)
| where EventName in (EventNameList) or EventName in (createPolicy)
| 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]), "");
//Checking for Policy creation event with Full Admin Privileges since lookback period.
let FullAdminPolicyEvents =  materialize(  EventInfo
| where TimeGenerated >= ago(lookback)
| where EventName in (createPolicy)
| extend PolicyName = tostring(parse_json(RequestParameters).policyName)
| extend Statement = parse_json(tostring((parse_json(RequestParameters).policyDocument))).Statement
| mvexpand Statement
| extend Action = parse_json(Statement).Action , Effect = tostring(parse_json(Statement).Effect), Resource = tostring(parse_json(Statement).Resource), Condition = tostring(parse_json(Statement).Condition)
| extend Action = tostring(Action)
| where Effect =~ "Allow" and (Action contains "kms:Create" and (Action contains "kms:Get" or Action contains "kms:Describe")  and (Action contains "kms:Disable" or Action contains "kms:Enable") and Action contains "kms:Delete") and Resource == "*" and Condition == ""
| distinct TimeGenerated, EventName, PolicyName, SourceIpAddress, UserIdentityArn,  RecipientAccountId, AccountName, AccountUPNSuffix
| project-rename StartTime = TimeGenerated  );
let PolicyAttach = materialize(  EventInfo
| where TimeGenerated >= ago(timeframe)
| where EventName in (EventNameList) and isempty(ErrorCode) and isempty(ErrorMessage)
| extend PolicyName = tostring(split(tostring(parse_json(RequestParameters).policyArn),"/")[1])
| summarize AttachEventCount=count(), StartTime = min(TimeGenerated), EndTime = max(TimeGenerated) by EventSource, EventName,   UserIdentityType , UserIdentityArn, SourceIpAddress, RecipientAccountId, AccountName, AccountUPNSuffix, PolicyName
| extend AttachEvent = pack("StartTime", StartTime, "EndTime", EndTime, "EventName", EventName, "UserIdentityType",   UserIdentityType, "SourceIpAddress", SourceIpAddress, "AccountName", AccountName, "AccountUPNSuffix", AccountUPNSuffix, "RecipientAccountId", RecipientAccountId, "UserIdentityArn", UserIdentityArn)
| project EventSource, PolicyName, AttachEvent, RecipientAccountId, AccountName, AccountUPNSuffix, AttachEventCount
);
// Joining the list of PolicyNames and checking if it has been attached to any Roles/Users/Groups.
// These Roles/Users/Groups will be Privileged and can be used by adversaries as pivot point for privilege escalation via multiple ways.
FullAdminPolicyEvents
| join kind=leftouter
(
    PolicyAttach
)
on PolicyName
| project-away PolicyName1
entityMappings:
- entityType: Account
  fieldMappings:
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  - identifier: CloudAppAccountId
    columnName: RecipientAccountId
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: SourceIpAddress
tactics:
- DefenseEvasion
- PrivilegeEscalation
- Persistence
requiredDataConnectors:
- dataTypes:
  - AWSCloudTrail
  connectorId: AWS
alertDetailsOverride:
  alertDisplayNameFormat: AWS KMS policy {{PolicyName}} created and attached by {{AccountName}}
  alertDescriptionFormat: Detected {{EventName}} for policy {{PolicyName}} in account {{RecipientAccountId}}.
id: 8e15998e-1e32-4b6d-abd1-e8482e8f3def
severity: Medium
status: Available
customDetails:
  RecipientAccountId: RecipientAccountId
  UserIdentityArn: UserIdentityArn
  EventName: EventName
  PolicyName: PolicyName
query: |
  let EventNameList = dynamic(["AttachUserPolicy","AttachRolePolicy","AttachGroupPolicy"]);
  let createPolicy =  dynamic(["CreatePolicy", "CreatePolicyVersion"]);
  let timeframe = 1d;
  let lookback = 14d;
  // Creating Master table with all the events to use with materialize for better performance
  let EventInfo = AWSCloudTrail
  | where TimeGenerated >= ago(lookback)
  | where EventName in (EventNameList) or EventName in (createPolicy)
  | 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]), "");
  //Checking for Policy creation event with Full Admin Privileges since lookback period.
  let FullAdminPolicyEvents =  materialize(  EventInfo
  | where TimeGenerated >= ago(lookback)
  | where EventName in (createPolicy)
  | extend PolicyName = tostring(parse_json(RequestParameters).policyName)
  | extend Statement = parse_json(tostring((parse_json(RequestParameters).policyDocument))).Statement
  | mvexpand Statement
  | extend Action = parse_json(Statement).Action , Effect = tostring(parse_json(Statement).Effect), Resource = tostring(parse_json(Statement).Resource), Condition = tostring(parse_json(Statement).Condition)
  | extend Action = tostring(Action)
  | where Effect =~ "Allow" and (Action contains "kms:Create" and (Action contains "kms:Get" or Action contains "kms:Describe")  and (Action contains "kms:Disable" or Action contains "kms:Enable") and Action contains "kms:Delete") and Resource == "*" and Condition == ""
  | distinct TimeGenerated, EventName, PolicyName, SourceIpAddress, UserIdentityArn,  RecipientAccountId, AccountName, AccountUPNSuffix
  | project-rename StartTime = TimeGenerated  );
  let PolicyAttach = materialize(  EventInfo
  | where TimeGenerated >= ago(timeframe)
  | where EventName in (EventNameList) and isempty(ErrorCode) and isempty(ErrorMessage)
  | extend PolicyName = tostring(split(tostring(parse_json(RequestParameters).policyArn),"/")[1])
  | summarize AttachEventCount=count(), StartTime = min(TimeGenerated), EndTime = max(TimeGenerated) by EventSource, EventName,   UserIdentityType , UserIdentityArn, SourceIpAddress, RecipientAccountId, AccountName, AccountUPNSuffix, PolicyName
  | extend AttachEvent = pack("StartTime", StartTime, "EndTime", EndTime, "EventName", EventName, "UserIdentityType",   UserIdentityType, "SourceIpAddress", SourceIpAddress, "AccountName", AccountName, "AccountUPNSuffix", AccountUPNSuffix, "RecipientAccountId", RecipientAccountId, "UserIdentityArn", UserIdentityArn)
  | project EventSource, PolicyName, AttachEvent, RecipientAccountId, AccountName, AccountUPNSuffix, AttachEventCount
  );
  // Joining the list of PolicyNames and checking if it has been attached to any Roles/Users/Groups.
  // These Roles/Users/Groups will be Privileged and can be used by adversaries as pivot point for privilege escalation via multiple ways.
  FullAdminPolicyEvents
  | join kind=leftouter
  (
      PolicyAttach
  )
  on PolicyName
  | project-away PolicyName1  
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_CreatedCRUDKMSPolicytoPrivilegeEscalation.yaml
kind: Scheduled
queryPeriod: 1d
version: 1.0.3
name: AWSCloudTrail - Creation of CRUD KMS policy and then privilege escalation
queryFrequency: 1d
triggerThreshold: 0
relevantTechniques:
- T1484
- T1098.003
description: |
  Identifies creation of IAM policies that grant permissions for broad KMS CRUD actions, followed by attachment activity to a principal. This sequence can be used to expand access to encryption keys or
  disable protections and should be investigated as possible privilege escalation.  
triggerOperator: gt