Browse Rules

AWS Lambda Event Source Mapping Creation

Identifies the creation of an AWS Lambda event source mapping, which connects an event source such as an Amazon SQS queue, an Amazon Kinesis or DynamoDB stream, an Amazon MSK or self-managed Apache Kafka topic, or an Amazon MQ broker to a Lambda function so the function is automatically invoked when new records arrive. Adversaries with "lambda:CreateEventSourceMapping" permissions can abuse this to establish stealthy, event-driven persistence and execution, or to continuously siphon records from

AWS Lambda Function Invoked from an Unusual Source ASN

Identifies an AWS Lambda function invoked directly by a principal from a source network (ASN) not seen for that principal in the prior 10 days, excluding common cloud provider networks. Direct invocation from an unfamiliar external network can indicate use of stolen execution-role or user credentials from attacker-controlled infrastructure to execute functions or retrieve the data they return. This rule relies on AWS Lambda data event logging, which is not enabled by default.

AWS Lambda Function High-Frequency Invocation by a Single Principal

Identifies a single principal directly invoking AWS Lambda functions at a high volume within a one-hour window. Adversaries may drive excessive invocations to abuse functions for resource hijacking or cryptomining, to inflate costs in a denial-of-wallet attack, or to enumerate function behavior. This is a volumetric heuristic: the threshold is environment-dependent and high-throughput applications can exceed it, so tune it to the deployment. This rule relies on AWS Lambda data event logging, whi

AWS Discovery API Calls via CLI from a Single Resource

Detects when a single AWS resource is running multiple read-only, discovery API calls in a 10-second window. This behavior could indicate an actor attempting to discover the AWS infrastructure using compromised credentials or a compromised instance. Adversaries may use this information to identify potential targets for further exploitation or to gain a better understanding of the target's infrastructure.

AWS Lambda Function Invoked by an Unusual Principal

Identifies the first time within the prior 14 days that a principal directly invokes an AWS Lambda function in an account, excluding invocations made on behalf of AWS services (normal event-source triggers). Adversaries who compromise credentials or move laterally may directly invoke functions to execute code, retrieve data returned by a function, or abuse an over-permissioned execution role. Direct, ad hoc invocation by a principal that does not normally call Lambda deviates from the usual even

AWS Lambda Layer Shared Externally

Identifies the modification of an AWS Lambda layer permission policy to grant another AWS account, an AWS Organization, or the public the ability to use a layer version. Lambda layers package code and dependencies that are loaded into the execution environment of any function that references them. Sharing a layer with an external account or with everyone can leak proprietary code or secrets bundled in the layer, and can serve as a supply-chain mechanism whereby downstream functions load attacker

AWS Lambda Function Created or Updated

Identifies when an AWS Lambda function is created or updated. AWS Lambda lets you run code without provisioning or managing servers. Adversaries can create or update Lambda functions to execute malicious code, exfiltrate data, or escalate privileges. This is a [building block rule](https://www.elastic.co/guide/en/security/current/building-block-rule.html) that does not generate alerts, but signals when a Lambda function is created or updated that matches the rule's conditions. To generate alerts

AWS Lambda Function Policy Updated to Allow Cross-Account Invocation

Identifies a change to an AWS Lambda function resource policy that grants invoke permissions to an AWS account principal. Using AddPermission, an adversary can authorize a principal in another account to call a function, creating a cross-account backdoor for execution or for relaying data to attacker-controlled infrastructure without modifying the function's code. This rule excludes public grants (principal set to "*"), which are covered by a separate rule, and grants to AWS service principals,

AWS Lambda Function Invoked Cross-Account

Identifies an AWS Lambda function invoked by a principal whose AWS account differs from the account that owns the function (a cross-account invocation). The caller's account is parsed from the invoking principal's ARN and compared to the function account. Adversaries who have been granted invoke permission on a function from an external account, or who operate from a separate attacker-controlled account, can use cross-account invocation to execute functions or retrieve the data they return. This

AWS Lambda Layer Added to Existing Function

Identifies when a Lambda layer is added to an existing AWS Lambda function. Lambda layers allow shared code, dependencies, or runtime modifications to be injected into a function’s execution environment. Adversaries with the ability to update function configurations may add a malicious layer to establish persistence, run unauthorized code, or intercept data handled by the function. This activity should be reviewed to ensure the modification is expected and authorized.

AWS IAM Sensitive Operations via Lambda Execution Role

Detects successful IAM API calls that create or empower IAM users and roles, attach or embed policies, or wire roles to instance profiles when the caller is an assumed role session associated with AWS Lambda. Serverless execution roles are often over-permissioned; an adversary who can run or compromise function code can abuse these APIs for privilege escalation and persistence—for example creating users or roles, issuing keys, attaching managed or inline policies, or preparing EC2 instance profi

AWS Bedrock Agent Created by IAM User or Root

Identifies AWS Bedrock Agent creation performed directly by an IAM user or the root account. Bedrock Agents are autonomous AI systems that execute multi-step tasks, invoke Lambda action groups to call external APIs, and query knowledge bases. Adversaries with access to an AWS account can create rogue agents configured to exfiltrate data via action group Lambda functions, pivot to other services, or act as a persistent AI-driven command-and-control channel. This rule is scoped to IAMUser and Root

AWS Lambda Function Deletion

Identifies the deletion of an AWS Lambda function. Deleting a function removes its code, configuration, versions, and aliases. Adversaries may delete functions to disrupt business operations and automated workflows, to destroy attacker-deployed backdoors and remove evidence after achieving their objective, or to inhibit incident response. Because function deletion is destructive and often irreversible without redeployment, deletions performed by unexpected principals or outside change windows sh

AWS Lambda Function URL Created with Public Access

Identifies the creation or update of an AWS Lambda function URL configured with an authentication type of NONE, which exposes the function to unauthenticated invocation directly from the public internet. Adversaries can use a public function URL to establish a durable, internet-reachable entry point for command and control, data egress, or on-demand execution of attacker-controlled code, bypassing the need for valid AWS credentials to invoke the function. Function URLs with public access should

AWS Bedrock Agent or Action Group Manipulation

Detects modification of deployed Amazon Bedrock agents and their action groups, collaborators, or aliases via the Bedrock Agent control plane. Adversaries with access to an AWS account can tamper with an existing, trusted agent by altering its instructions (UpdateAgent), adding or changing action groups that wire the agent to Lambda functions or APIs (CreateAgentActionGroup, UpdateAgentActionGroup), attaching or modifying collaborators (AssociateAgentCollaborator, UpdateAgentCollaborator), or re

AWS Lambda Function Policy Updated to Allow Public Invocation

Identifies when an AWS Lambda function policy is updated to allow public invocation. This rule detects use of the AddPermission API where the Principal is set to "*", enabling any AWS account to invoke the function. Adversaries may abuse this configuration to establish persistence, create a covert execution path, or operate a function as an unauthenticated backdoor. Public invocation is rarely required outside very specific workloads and should be considered high-risk when performed unexpectedly

AWS Route 53 Resolver Query Log Configuration Deleted

Identifies the deletion of an Amazon Route 53 Resolver Query Log Configuration. Resolver query logs provide critical visibility into DNS activity across VPCs, including lookups made by EC2 instances, containers, Lambda functions, and other AWS resources. Deleting a query log configuration immediately stops DNS query and response logging for the associated VPC. Adversaries may delete these configurations to evade detection, suppress forensic evidence, or degrade security monitoring capabilities.

AWS SNS Rare Protocol Subscription by User

Identifies when a user subscribes to an SNS topic using a new protocol type (ie. email, http, lambda, etc.). SNS allows users to subscribe to recieve topic messages across a broad range of protocols like email, sms, lambda functions, http endpoints, and applications. Adversaries may subscribe to an SNS topic to collect sensitive information or exfiltrate data via an external email address, cross-account AWS service or other means. This rule identifies a new protocol subscription method for a par

First Time Seen AWS Secret Value Accessed in Secrets Manager

An adversary with access to a compromised AWS service such as an EC2 instance, Lambda function, or other service may attempt to leverage the compromised service to access secrets in AWS Secrets Manager. This rule looks for the first time a specific user identity has programmatically retrieved a secret value from Secrets Manager using the GetSecretValue action. This rule assumes that AWS services such as Lambda functions and EC2 instances are setup with IAM role's assigned that have the necessary

AWS Service Quota Increase Requested by Rare Identity

Detects the first time an AWS identity requests a service quota increase via the AWS Service Quotas API within a 7-day history window. Service quota increases are submitted to AWS Support and, when approved, raise the limits on EC2 instances, Lambda concurrency, VPC resources, and other services. An adversary who obtains AWS credentials may request quota increases as infrastructure preparation for large-scale cryptomining, DDoS amplification, phishing campaigns, or data exfiltration operations t

AWS EventBridge Rule Disabled or Deleted

Identifies when an Amazon EventBridge rule is disabled or deleted. EventBridge rules are commonly used to automate operational workflows and security-relevant routing (for example, forwarding events to Lambda, SNS/SQS, or security tooling). Disabling or deleting a rule can break critical integrations, suppress detections, and reduce visibility. Adversaries may intentionally impair EventBridge rules to disrupt monitoring, delay response, or hide follow-on actions.