Malicious Python Package Uses Unicode Trickery to Evade Detection and Steal Data

Mar 24, 2023Ravie LakshmananDevSecOps / Software Security

A malicious Python package on the Python Package Index (PyPI) repository has been found to use Unicode as a trick to evade detection and deploy an info-stealing malware.

The package in question, named onyxproxy, was uploaded to PyPI on March 15, 2023, and comes with capabilities to harvest and exfiltrate credentials and other valuable data. It has since been taken down, but not before attracting a total of 183 downloads.

According to software supply chain security firm Phylum, the package incorporates its malicious behavior in a setup script that’s packed with thousands of seemingly legitimate code strings.

These strings include a mix of bold and italic fonts and are still readable and can be parsed by the Python interpreter, only to activate the execution of the stealer malware upon installation of the package.

“An obvious and immediate benefit of this strange scheme is readability,” the company noted. “Moreover, these visible differences do not prevent the code from running, which it does.”

This is made possible owing to the use of Unicode variants of what appears to be the same character (aka homoglyphs) to camouflage its true colors (e.g., self vs. 𝘀𝘦𝘭𝘧) among innocuous-looking functions and variables.

The use of Unicode to inject vulnerabilities into source code was previously disclosed by Cambridge University researchers Nicholas Boucher and Ross Anderson in an attack technique dubbed Trojan Source.

What the method lacks in sophistication, it makes up for it by creating a novel piece of obfuscated code, despite exhibiting telltale signs of copy-paste efforts from other sources.

WEBINAR

Discover the Hidden Dangers of Third-Party SaaS Apps

Are you aware of the risks associated with third-party app access to your company’s SaaS apps? Join our webinar to learn about the types of permissions being granted and how to minimize risk.

RESERVE YOUR SEAT

The development highlights continued attempts on part of threat actors to find new ways to slip through string-matching based defenses, leveraging “how the Python interpreter handles Unicode to obfuscate their malware.”

On a related note, Canadian cybersecurity company PyUp detailed the discovery of three new fraudulent Python packages – aiotoolbox, asyncio-proxy, and pycolorz – that were downloaded cumulatively over 1,000 times and designed to retrieve obfuscated code from a remote server.

Found this article interesting? Follow us on Twitter and LinkedIn to read more exclusive content we post.
Cyber Security

Articles You May Like

Best Deals on Budget Wearables at Croma
SBF sentencing live updates: FTX founder says he made ‘selfish decisions’ at failed crypto exchange
Adam Neumann submits bid of more than $500 million to buy WeWork
China-Linked Group Breaches Networks via Connectwise, F5 Software Flaws
OnePlus Buds V With 12.4mm Titanium Plated Drivers, IP55 Rating Launched: Price, Specifications

Leave a Reply

Your email address will not be published. Required fields are marked *