AWSCloudTrail - Privilege escalation via Lambda policy

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Id	8e01c41d-bd4c-4bbe-aed5-18592735052d
Rulename	AWSCloudTrail - Privilege escalation via Lambda policy
Description	Detects inline IAM policy updates that grant broad AWS Lambda permissions, including combinations that can link Lambda with other services such as DynamoDB. These permissions can provide execution control and support privilege escalation paths in the cloud environment.
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 Web Services/Analytic Rules/AWS_PrivilegeEscalationViaLambdaPolicy.yaml
Version	1.0.2
Arm template	8e01c41d-bd4c-4bbe-aed5-18592735052d.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 "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:*") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:CreateFunction" and Action contains "lambda:InvokeFunction") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:Create*" and Action contains "lambda:Invoke*")) or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:*" and Action contains "dynamodb:*") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:CreateFunction" and Action contains "lambda:CreateEventSourceMapping" and Action contains "dynamodb:PutItem" and Action contains "dynamodb:CreateTable") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:Create*" and Action contains "dynamodb:Put*" and Action contains "dynamodb:Create*")) 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

version: 1.0.2
id: 8e01c41d-bd4c-4bbe-aed5-18592735052d
relevantTechniques:
- T1098.003
requiredDataConnectors:
- connectorId: AWS
  dataTypes:
  - AWSCloudTrail
alertDetailsOverride:
  alertDescriptionFormat: Detected {{EventName}} Event, updating inline Lambda escalation policy {{PolicyName}} in account {{RecipientAccountId}}.
  alertDisplayNameFormat: AWS Lambda privilege escalation policy update by {{AccountName}}
triggerOperator: gt
entityMappings:
- fieldMappings:
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
  - columnName: RecipientAccountId
    identifier: CloudAppAccountId
  entityType: Account
- fieldMappings:
  - columnName: SourceIpAddress
    identifier: Address
  entityType: IP
name: AWSCloudTrail - Privilege escalation via Lambda policy
queryFrequency: 1d
triggerThreshold: 0
customDetails:
  UserIdentityArn: UserIdentityArn
  PolicyName: PolicyName
  EventName: EventName
  RecipientAccountId: RecipientAccountId
description: |
  Detects inline IAM policy updates that grant broad AWS Lambda permissions, including combinations that can
  link Lambda with other services such as DynamoDB. These permissions can provide execution control and support
  privilege escalation paths in the cloud environment.  
status: Available
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_PrivilegeEscalationViaLambdaPolicy.yaml
queryPeriod: 1d
severity: Medium
kind: Scheduled
tactics:
- PrivilegeEscalation
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 "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:*") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:CreateFunction" and Action contains "lambda:InvokeFunction") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:Create*" and Action contains "lambda:Invoke*")) or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:*" and Action contains "dynamodb:*") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:CreateFunction" and Action contains "lambda:CreateEventSourceMapping" and Action contains "dynamodb:PutItem" and Action contains "dynamodb:CreateTable") or ((Action contains "iam:*" or Action contains "iam:PassRole") and Action contains "lambda:Create*" and Action contains "dynamodb:Put*" and Action contains "dynamodb:Create*")) 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