Attach a Malicious Lambda Layer¶
| Platform | Author | Last Update |
|---|---|---|
| aws | Nick Jones | 2023-07-01 |
An attacker may attach a Lambda layer to an existing function to override a library that is used by the function, and use that malicious code to execute AWS API calls with that functions function's IAM role.
MITRE IDs¶
Required Permissions¶
- lambda:UpdateFunctionConfiguration
Required Parameters¶
| Name | Type | Description | Example Value |
|---|---|---|---|
| functionname | str | Name of the function to be targeted | example-function |
| layers | str | List of layers to add as space-separated ARNs | arn:aws:lambda:us-east-1:123456789012:layer:my-layer |
Attacker Action¶
aws lambda update-function-configuration --function-name example-function --layers arn:aws:lambda:us-east-1:123456789012:layer:my-layer
Detection Case¶
ELK query¶
When logs are ingested into ELK, the following Lucene query can be used to identify relevant events.
eventName:UpdateFunctionConfiguration AND eventSource:lambda.amazonaws.com
Sigma Definition¶
---
title: Attach a Malicious Lambda Layer
id: 8fb105ea-19f8-4537-965a-cdc68200b8d9
status: experimental
author: Nick Jones
date: 2023-07-01
description: An attacker may attach a Lambda layer to an existing function to override a library that is used by the function, and use that malicious code to execute AWS API calls with that functions function's IAM role.
logsource:
service: cloudtrail
detection:
selection_source:
- eventSource: "lambda.amazonaws.com"
events:
- eventName: "UpdateFunctionConfiguration"
condition: selection_source AND events
level: medium
tags:
- attack.T1525
references:
- https://docs.aws.amazon.com/lambda/latest/dg/API_UpdateFunctionConfiguration.html
- https://docs.aws.amazon.com/cli/latest/reference/lambda/update-function-configuration.html