Malicious Roblox Cookie and Discord Token Stealers Hit PyPI Repository

February 02, 2022 By Ax Sharma

5 minute read time

Over the past few years, Sonatype had consistently been on top of discovering malicious packages infiltrating open source ecosystems like npm, PyPI, and GitHub. Among various examples, this has included Discord token and credit card stealers previously caught on the npm registry by our automated malware detection system, Nexus Firewall.

And, just last week, we reported that the PyPI repository had been flooded with more than 1200 dependency confusion packages that served no functional purpose.

This week, our early warning systems have once again caught malicious PyPI packages that steal your Roblox security cookies and Discord tokens. These packages shown below are accounted for in Sonatype’s security data under sonatype-2022-0706, and sonatype-2022-0723.

Package (Downloads)

Author

Purpose

Description

xss
(2,246)

HeyDeveloper aka Drake

Typosquatting

Discord token stealers, not a PoC for an “XSS” attack as the package claims

Easyfuncsys
(975)

Xin1337

Possible typosquat of a legitimate package

Steals Discord token and leveldb files, runs a suspicious EXE

Humanqueen
(455)

Xin1337

Unclear

Steals Discord token and leveldb files

Humanqueenn
(240)

Xin1337

Unclear

Steals Discord token and leveldb files

 

According to PePy stats, these packages have been retrieved a total of 3,916 times—this includes downloads from PyPI users and automated mirrors.

On discovering these packages this week, we rushed our findings to the PyPI security team who have since removed the packages.

Roblox Security Cookie Stealer

As gaming platforms like Discord and Roblox have gained popularity and rapid adoption, threat actors continue to target users and devs of these platforms through techniques like typosquatting or brandjacking, as Sonatype has previously reported.

However, the packages caught by us this time are of a quirky nature.

Starting with the PyPI package ‘xss,’ for example, we see it touts itself to be a “simple XSS toolkit.”

roblox cookie stealing PyPI package, 'xss'

Screenshot of the XSS Project page

For those unfamiliar with the term Cross-Site Scripting (XSS), its a form of attack exploited by the bad actor sending malicious code to the user’s web browser via a web application. For example, a simple XSS example would be you clicking on a link sent by the attacker, and this link opens a legitimate website, but sends your session cookies, for that website, to the attacker.

Although the ‘xss’ package may appear to be an ‘XSS toolkit’ that can be used by security professionals and pen-testers to create XSS exploits, the contents don’t quite convey that.

My colleagues, Cody Nash who’s part of the development team behind the automated malware detection system, and security researcher Juan Aguirre, noticed “xss” versions 0.0.7 and 0.0.8 look for your ROBLOSECURITY cookie and send it to the attacker via a Discord webhook:

code inside pypi package 'xss'

The ‘ROBLOSECURITY’ cookie is a sensitive piece of information stored by Roblox on the logged-in user’s web browser to track their sessions. The cookie should never be shared with anyone as attackers who can access your ‘ROBLOSECURITY’ cookie can potentially gain access to your account straight away.  This would bypass any two-step verification checks you’ve set up.

Good Old Discord Token Stealers

The second category of PyPI packages identified by us is Discord token stealers:

malicious pypi packages by xin1337

All of the three packages contain identical code. ‘Easyfuncsys,’ with its vague description of “Sniping names” in particular appears to be a typosquat given that a similarly named legitimate package called easyfunctions exists.

It isn’t imminently clear what prompted the attacker to name the other two, ‘humanqueen’ and ‘humanqueenn.’ But, our review suggests that these two packages are used as a testing ground by the attacker whose main goal is to have users install ‘easyfuncsys.’

For ‘easyfuncsys’, the initial versions peek inside your web browsers’ local storage (‘leveldb’) files, a technique identical to what we have seen in previous attacks

easyfuncsys code

Further, Discord tokens from these files are retrieved and sent to the attacker’s webhook.

Later versions of 'easyfuncsys,’ however left us surprised as these specifically targeted Windows users. These versions, upon installation, simply downloaded and ran a suspicious EXE on the victim’s machine.

mb-nmEt1MWg43TT6e5zuAteSrF5VFqI3V6QINvbK5bxw9UasuPcDwOV8BoOAXhq-scoM4QFm8uHOeT1gnT2dpnGEocqDKOsUDzu89kYxP4UZX13Q3Fj0xbZ5u2u_mwmYi697mpaS

Nexus Firewall Users Protected

Users of Nexus Firewall can rest easy knowing that such malicious packages would automatically be blocked from reaching their development builds. 

U-cofx0-oAHuk7B8hQ_0YBbx7E9LQSW04uag5iP4Q7mdyUWkjohGvAiYYykP8LnvXzbz7CUADYOIt3X4KVAozG7Sxz7PFEffVVl_TP2LufuKfXcPzVvjvk3Br_IPtFK9776-HbUE

Nexus Firewall instances will automatically quarantine any suspicious components detected by our automated malware detection systems while a manual review by a researcher is in the works, thereby keeping your software supply chain protected from the start. Furthermore, Sonatype’s customers with the Advance Development Pack benefit from the additional protection offered by our automated malware detection systems and world-class security research data.

Sonatype’s world-class security research data, combined with our automated malware detection technology safeguards your developers, customers, and software supply chain from infections.

Tags: vulnerabilities, featured, DevZone

Written by Ax Sharma

Ax is a Security Researcher at Sonatype and Engineer who holds a passion for perpetual learning. His works and expert analyses have frequently been featured by leading media outlets. Ax's expertise lies in security vulnerability research, reverse engineering, and software development. In his spare time, he loves exploiting vulnerabilities ethically and educating a wide range of audiences.