AWSCloudTrail - Privilege escalation via CRUD Lambda policy

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Id	d0953d50-3dc1-4fa3-80fa-4d3e973a0959
Rulename	AWSCloudTrail - Privilege escalation via CRUD Lambda policy
Description	Detects inline IAM policy updates that grant broad AWS Lambda lifecycle permissions and related destructive capabilities. This behavior can establish execution control paths and may indicate privilege escalation through unauthorized policy expansion.
Severity	Medium
Tactics	PrivilegeEscalation
Techniques	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_PrivilegeEscalationViaCRUDLambdaPolicy.yaml
Version	1.0.2
Arm template	d0953d50-3dc1-4fa3-80fa-4d3e973a0959.json

KQL

AWSCloudTrail
| where EventName in ("PutUserPolicy","PutRolePolicy","PutGroupPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
| 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 "kms:Delete") and Resource == "*" and Condition == ""
| 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]), "")
| distinct TimeGenerated, EventName, PolicyName, SourceIpAddress, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityArn, UserIdentityUserName

YAML

customDetails:
  RecipientAccountId: RecipientAccountId
  EventName: EventName
  PolicyName: PolicyName
  UserIdentityArn: UserIdentityArn
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
  - columnName: RecipientAccountId
    identifier: CloudAppAccountId
- entityType: IP
  fieldMappings:
  - columnName: SourceIpAddress
    identifier: Address
tactics:
- PrivilegeEscalation
status: Available
queryPeriod: 1d
queryFrequency: 1d
requiredDataConnectors:
- connectorId: AWS
  dataTypes:
  - AWSCloudTrail
severity: Medium
relevantTechniques:
- T1098.003
name: AWSCloudTrail - Privilege escalation via CRUD Lambda policy
kind: Scheduled
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon%20Web%20Services/Analytic%20Rules/AWS_PrivilegeEscalationViaCRUDLambdaPolicy.yaml
description: |
  Detects inline IAM policy updates that grant broad AWS Lambda lifecycle permissions and related destructive
  capabilities. This behavior can establish execution control paths and may indicate privilege escalation through
  unauthorized policy expansion.
triggerOperator: gt
alertDetailsOverride:
  alertDescriptionFormat: Detected {{EventName}} Event, updating inline Lambda escalation policy {{PolicyName}} in account {{RecipientAccountId}}.
  alertDisplayNameFormat: AWS Lambda privilege escalation policy update by {{AccountName}}
id: d0953d50-3dc1-4fa3-80fa-4d3e973a0959
version: 1.0.2
triggerThreshold: 0
query: |
  AWSCloudTrail
  | where EventName in ("PutUserPolicy","PutRolePolicy","PutGroupPolicy") and isempty(ErrorCode) and isempty(ErrorMessage)
  | 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 "kms:Delete") and Resource == "*" and Condition == ""
  | 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]), "")
  | distinct TimeGenerated, EventName, PolicyName, SourceIpAddress, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityArn, UserIdentityUserName

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/d0953d50-3dc1-4fa3-80fa-4d3e973a0959')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/d0953d50-3dc1-4fa3-80fa-4d3e973a0959')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "Detected {{EventName}} Event, updating inline Lambda escalation policy {{PolicyName}} in account {{RecipientAccountId}}.",
          "alertDisplayNameFormat": "AWS Lambda privilege escalation policy update by {{AccountName}}"
        },
        "alertRuleTemplateName": "d0953d50-3dc1-4fa3-80fa-4d3e973a0959",
        "customDetails": {
          "EventName": "EventName",
          "PolicyName": "PolicyName",
          "RecipientAccountId": "RecipientAccountId",
          "UserIdentityArn": "UserIdentityArn"
        },
        "description": "Detects inline IAM policy updates that grant broad AWS Lambda lifecycle permissions and related destructive\ncapabilities. This behavior can establish execution control paths and may indicate privilege escalation through\nunauthorized policy expansion.\n",
        "displayName": "AWSCloudTrail - Privilege escalation via CRUD Lambda policy",
        "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_PrivilegeEscalationViaCRUDLambdaPolicy.yaml",
        "query": "AWSCloudTrail\n| where EventName in (\"PutUserPolicy\",\"PutRolePolicy\",\"PutGroupPolicy\") and isempty(ErrorCode) and isempty(ErrorMessage)\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 \"kms:Delete\") and Resource == \"*\" and Condition == \"\"\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| distinct TimeGenerated, EventName, PolicyName, SourceIpAddress, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityArn, UserIdentityUserName\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [
          "T1098.003"
        ],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "PrivilegeEscalation"
        ],
        "techniques": [
          "T1098"
        ],
        "templateVersion": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}