Millions of JS devs just got penetrated by a RAT…

If you're a JavaScript developer, I have some bad news. But put down your artisal soy milk latte and find a safe space to watch this video because it will almost certainly make you cry. I can hardly keep it together myself because yesterday a precisiong guided remote access Trojan or RAT was discovered in Axios, a library with over 100 million weekly downloads on npm. For over a decade, countless developers have turned to Axios to improve the developer experience when making HTTP requests in Node.js in the browser. But now that improved developer experience just turned into non-consentual backdoor penetration by a magnumsized Trojan. The two different malicious versions of Axios were published to the MPM registry that contained a highly sophisticated supply chain attack that compromises developer machines and CI/CD servers. If you use Axios and are running either of these versions, the quick fix is to go into your garage, find a sledgehammer, destroy your machine, fake your own death, and then move to a remote village in the Siberian tundra. And I'm not exaggerating. If your system is compromised, the rat could already have access to your AWS credentials, your OpenAI API keys, and everything else in your file. It's a bad one. And in today's video, we'll break down one of the most sophisticated npm hacks the world has ever seen. It is March 31st, 2026, and you're watching the code report. Over 10 years ago, Axios became extremely popular after it made HTTP requests promise-based instead of callback based. But now today, every JavaScript runtime supports fetch natively, which in theory should have made Axios obsolete. Yet many developers still prefer to use this thirdparty library over the native web platform. Unfortunately though, optimizing for DX with a third party library just went horribly wrong. And the scariest thing is that Axios itself contains zero lines of bad source code. Instead of just hard- coding a crypto miner into the package like a noob, the attacker slipped a rogue dependency into the release. It triggered a post install script that pulled down a remote access Trojan from a command and control server that then wiped its own footprints so everything looked clean after the install. Before we go into details though, let's take a minute to find out if you've been penetrated. First, go into your package JSON file and find out if you have either of these versions of Axios installed. If you answered yes, this package may have run a postinstall script to install another package called plain-crypto-JS. Then go into your node modules and see if you have this package installed there. If your project tests positive for this package, you can then run these commands from Mac, Windows, and Linux to find out if there's an actual RAT living on your machine or remote access Trojan. If the RAT file is found, you are screwed. Your system is compromised, and simply deleting the RAT is not enough. You'll want to immediately roll all API keys and tokens and follow this guide over at Step Security for more instructions. But the big question is, how did this even happen? Well, it starts almost the same way every other hack starts. that the project maintainer's npm account was compromised. Normally releases are published with a GitHub action, but in the malicious versions, they were published under a Proton Mail address. The attacker obtained an npm access token to publish these packages, but how they actually obtained it is unclear at this point. In any case, the attacker maintained another package called plain crypto.js that looks identical to the legitimate cryptojs package. Most importantly, the bad version of this package contains a post install script that runs some JavaScript code to install the RAT on your machine. It's called the rat dropper. And although the code was obiscated, is step security was able to analyze it. The rat dropper works by piggybacking on npm installs life cycle. The script will first detect the system you're running, then reach out to a remote command and control server where it can fetch a second stage payload tailored to your operating system. Once downloaded, it then writes the payload to disk that then executes it to establish remote access at which point it can steal your credentials remotely and do all kinds of other bad stuff. And then finally, it cleans up after itself to avoid detection. It deletes itself. It deletes the package JSON and removes the post install script among other things so that the end result is running mpm audit that doesn't raise any red flags. 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Thanks for watching, and I will see you in the next one.

Mux is the best video API for developers. Get $50 in free credits - https://mux.com/fireship Yesterday, a precision-guided remote access trojan was discovered in Axios, a JavaScript library with over 100 million downloads on npm. But this wasn't your average RAT - let's take a look at how this highly sophisticated attack was pulled off and what to do if you're compromised. #coding #programming #hack ℹ️ More Info: - https://www.stepsecurity.io/blog/axios-compromised-on-npm-malicious-versions-drop-remote-access-trojan 🔖 Topics Covered - What is Axios - Axios RAT attack - What to do if you're compromised Want more Fireship? 🗞️ Newsletter: https://bytes.dev 🧠 Courses: https://fireship.dev