AWSCloudTrail - Creation of CRUD Lambda policy and then privilege escalation

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Id	22115d3c-e87c-485a-9130-33797d619124
Rulename	AWSCloudTrail - Creation of CRUD Lambda policy and then privilege escalation
Description	Identifies creation of IAM policies that grant broad AWS Lambda CRUD permissions and subsequent policy attachment activity to a principal. This behavior may indicate an attempt to add capabilities that support privilege escalation or unauthorized execution pathways.
Severity	Medium
Tactics	DefenseEvasion PrivilegeEscalation Persistence
Techniques	T1484 T1098.003
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%20Web%20Services/Analytic%20Rules/AWS_CreatedCRUDLambdaPolicytoPrivilegEscalation.yaml
Version	1.0.4
Arm template	22115d3c-e87c-485a-9130-33797d619124.json

KQL

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 "lambda:Create" and Action contains "lambda:Get" and Action contains "lambda:Update" and Action contains "lambda: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

YAML

entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
  - columnName: RecipientAccountId
    identifier: CloudAppAccountId
- entityType: IP
  fieldMappings:
  - columnName: SourceIpAddress
    identifier: Address
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 "lambda:Create" and Action contains "lambda:Get" and Action contains "lambda:Update" and Action contains "lambda: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
id: 22115d3c-e87c-485a-9130-33797d619124
queryFrequency: 1d
alertDetailsOverride:
  alertDisplayNameFormat: 'AWS Lambda privilege escalation policy activity: {{PolicyName}} by {{AccountName}}'
  alertDescriptionFormat: Detected {{EventName}} for policy {{PolicyName}} in account {{RecipientAccountId}}.
status: Available
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon%20Web%20Services/Analytic%20Rules/AWS_CreatedCRUDLambdaPolicytoPrivilegEscalation.yaml
version: 1.0.4
severity: Medium
relevantTechniques:
- T1484
- T1098.003
name: AWSCloudTrail - Creation of CRUD Lambda policy and then privilege escalation
kind: Scheduled
tactics:
- DefenseEvasion
- PrivilegeEscalation
- Persistence
requiredDataConnectors:
- dataTypes:
  - AWSCloudTrail
  connectorId: AWS
description: |
  Identifies creation of IAM policies that grant broad AWS Lambda CRUD permissions and subsequent policy attachment
  activity to a principal. This behavior may indicate an attempt to add capabilities that support privilege
  escalation or unauthorized execution pathways.
customDetails:
  RecipientAccountId: RecipientAccountId
  EventName: EventName
  UserIdentityArn: UserIdentityArn
  PolicyName: PolicyName
triggerOperator: gt
triggerThreshold: 0
queryPeriod: 1d

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/22115d3c-e87c-485a-9130-33797d619124')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/22115d3c-e87c-485a-9130-33797d619124')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "Detected {{EventName}} for policy {{PolicyName}} in account {{RecipientAccountId}}.",
          "alertDisplayNameFormat": "AWS Lambda privilege escalation policy activity: {{PolicyName}} by {{AccountName}}"
        },
        "alertRuleTemplateName": "22115d3c-e87c-485a-9130-33797d619124",
        "customDetails": {
          "EventName": "EventName",
          "PolicyName": "PolicyName",
          "RecipientAccountId": "RecipientAccountId",
          "UserIdentityArn": "UserIdentityArn"
        },
        "description": "Identifies creation of IAM policies that grant broad AWS Lambda CRUD permissions and subsequent policy attachment\nactivity to a principal. This behavior may indicate an attempt to add capabilities that support privilege\nescalation or unauthorized execution pathways.\n",
        "displayName": "AWSCloudTrail - Creation of CRUD Lambda policy and then privilege escalation",
        "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%20Web%20Services/Analytic%20Rules/AWS_CreatedCRUDLambdaPolicytoPrivilegEscalation.yaml",
        "query": "let EventNameList = dynamic([\"AttachUserPolicy\",\"AttachRolePolicy\",\"AttachGroupPolicy\"]);\nlet createPolicy =  dynamic([\"CreatePolicy\", \"CreatePolicyVersion\"]);\nlet timeframe = 1d;\nlet lookback = 14d;\n// Creating Master table with all the events to use with materialize for better performance\nlet EventInfo = AWSCloudTrail\n| where TimeGenerated >= ago(lookback)\n| where EventName in (EventNameList) or EventName in (createPolicy)\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//Checking for Policy creation event with Full Admin Privileges since lookback period.\nlet FullAdminPolicyEvents =  materialize(  EventInfo\n| where TimeGenerated >= ago(lookback)\n| where EventName in (createPolicy)\n| extend PolicyName = tostring(parse_json(RequestParameters).policyName)\n| extend Statement = parse_json(tostring((parse_json(RequestParameters).policyDocument))).Statement\n| mvexpand Statement\n| extend Action = parse_json(Statement).Action , Effect = tostring(parse_json(Statement).Effect), Resource = tostring(parse_json(Statement).Resource), Condition = tostring(parse_json(Statement).Condition)\n| extend Action = tostring(Action)\n| where Effect =~ \"Allow\" and (Action contains \"lambda:Create\" and Action contains \"lambda:Get\" and Action contains \"lambda:Update\" and Action contains \"lambda:Delete\") and Resource == \"*\" and Condition == \"\"\n| distinct TimeGenerated, EventName, PolicyName, SourceIpAddress, UserIdentityArn, RecipientAccountId, AccountName, AccountUPNSuffix\n| project-rename StartTime = TimeGenerated  );\nlet PolicyAttach = materialize(EventInfo\n| where TimeGenerated >= ago(timeframe)\n| where EventName in (EventNameList) and isempty(ErrorCode) and isempty(ErrorMessage)\n| extend PolicyName = tostring(split(tostring(parse_json(RequestParameters).policyArn),\"/\")[1])\n| summarize AttachEventCount=count(), StartTime = min(TimeGenerated), EndTime = max(TimeGenerated) by EventSource, EventName, UserIdentityType , UserIdentityArn, SourceIpAddress, RecipientAccountId, AccountName, AccountUPNSuffix, PolicyName\n| extend AttachEvent = pack(\"StartTime\", StartTime, \"EndTime\", EndTime, \"EventName\", EventName, \"UserIdentityType\",   UserIdentityType, \"SourceIpAddress\", SourceIpAddress, \"AccountName\", AccountName, \"AccountUPNSuffix\", AccountUPNSuffix, \"RecipientAccountId\", RecipientAccountId, \"UserIdentityArn\", UserIdentityArn)\n| project EventSource, PolicyName, AttachEvent, RecipientAccountId, AccountName, AccountUPNSuffix, AttachEventCount\n);\n// Joining the list of PolicyNames and checking if it has been attached to any Roles/Users/Groups.\n// These Roles/Users/Groups will be Privileged and can be used by adversaries as pivot point for privilege escalation via multiple ways.\nFullAdminPolicyEvents\n| join kind=leftouter\n(\n    PolicyAttach\n)\non PolicyName\n| project-away PolicyName1\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [
          "T1098.003"
        ],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion",
          "Persistence",
          "PrivilegeEscalation"
        ],
        "techniques": [
          "T1098",
          "T1484"
        ],
        "templateVersion": "1.0.4",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}