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Unmasking Lambda's Hidden Threat - When Your Bootstrap Becomes a Backdoor

Lambda Bootstrap

So, you've jumped on the serverless bandwagon, huh? All that auto-scaling, no servers to patch, just pure code magic. It feels invincible, right? Well, sorry to burst your bubble, but even in the land of ephemeral functions, bad actors are finding ways to stick around longer than an awkward family dinner. Today, we're pulling back the curtain on one of those particularly sneaky tricks: achieving persistence in AWS Lambda by messing with its very heart – the custom runtime bootstrap file.

Stealthy Persistence in AWS - A Practical Simulation for Defenders

In the world of cloud cybersecurity, attackers are always innovating. As defenders, it's crucial not only to understand attack techniques but also to simulate them to strengthen our own defenses. Recently, an analysis from Datadog and insights from a security analyst Eduard Agavriloae shed light on a particularly cunning persistence technique in AWS: the use of API Gateway and Lambda Functions for credential exfiltration, with a "twist" that makes it even harder to detect.

This article breaks down how an attacker might implement this technique and, more importantly, how we can simulate it in our own environment to fine-tune our detection and prevention capabilities.

  • in IAM, S3
  • 3 min read

IAM Access Analyzer - A Cloud Guardian for Your S3 Buckets

IAM Access Analyzer

In the vast and ever-expanding AWS ecosystem, permission management is crucial. A simple misconfiguration in an S3 bucket policy can expose sensitive data, opening a backdoor for attackers. This is where IAM Access Analyzer steps in, acting as an unyielding sentinel to protect your resources by detecting unwanted external access.

Defending S3 - Anatomy and Countermeasures for Encryption and Deletion Attacks (Codefinger ransomware)

Lately, we're seeing an attack pattern against Amazon S3 that is brutally simple and effective. Attackers don't need a zero-day exploit in AWS. They just need one thing: a set of compromised AWS credentials. With that, they can either delete or hijack all your data.

In this post, we're going to break down the anatomy of two specific tactics gaining popularity and, more importantly, walk through the defense playbook to make sure it doesn't happen to you. Because under the shared responsibility model, whether your data in S3 is still there tomorrow depends on the defenses you implement today.

S3 Ransomware Batch Deletion Attack

Introduction

As an AWS security consultant, I've observed the devastating effects of ransomware on AWS S3 buckets. A particularly effective technique employed by attackers involves leveraging the S3 DeleteObjects API for batch deletion. In this post, I'll share my insights on how this attack unfolds and, more importantly, what measures you can implement to safeguard your data.