Eval all the strings! - Hardened JavaScript

Node Congress

Node Congress 2023

Zbyszek Tenerowicz

I Run Code From the Internet!

React Summit

React Summit 2023

React Advanced

React Advanced 2023

Watch Me Run Malware From NPM

JSNation US

JSNation US 2024

React Summit 2025

Malicious code is out to get you. Can you keep your app working as expected and hold on to your secrets? Come to this workshop and try!The entire workshop will be delivered as bite-sized hands-on exercises where increasingly advanced threats are presented and you get to defend.  No matter if you're concerned with malicious npm packages or building software to run other people's code, techniques presented in this workshop can be used to isolate JavaScript at runtime and protect against prototype poisoning. We'll explore techniques allowing cooperation with packages that intend to steal your secrets and mess with built-in functionality of JavaScript via prototype-poisoning.Another part of the workshop will focus on using tools to isolate code and scale the defensive coding practice up for larger codebases. If you're not dealing with security-critical code, it's a great opportunity to expand your awareness of rarely explored areas of JavaScript knowledge.

Defensive Coding

Watch me run real obfuscated malware from NPM safely while revealing what it does.  Learn how it's possible and use the technology behind it to secure your application from malicious code that gets past your audits and detections. And if obfuscation is not enough, watch it applied to a malware payload delivered as pre-compiled V8 bytecode with no source code provided for it.

Is it wise to run code from strangers? Well, we do it all the time and there's no backing out of it. Let's take a look at how a JavaScript project could get hacked and then defend itself from supply chain attacks.  Limit access to globals for each package? Sure. Control if a package can access network or file system? Yup, that too. And no more install scripts or prototype pollution.

Is it wise to run code from strangers? Well, we do it all the time and there's no backing out of it. Let's take a look at how a JavaScript project could get hacked and then defend itself from supply chain attacks. Limit access to globals for each package? Sure. Control if a package can access network or file system? Yup, that too. And no more install scripts or prototype pollution.

This talk is about SecureEcmaScript and Compartments which are TC39 proposals, and I'm working on tooling to make these concepts usable with people championing those proposals. This is a first-hand account of the future of JavaScript security. SES + tooling (LavaMoat or Endo) is making limiting access to network, fs, core modules or globals possible on a per-package basis. I want to show how they work, what possibilities they open and how to make that future happen today with some effort. To me this is the final step in securing npm supply chain - even if a package gets taken over by bad actors, it won't be able to hurt me.