LmCast :: Stay tuned in

Backdoored Telnyx PyPI package pushes malware hidden in WAV audio

Recorded: March 28, 2026, 1 a.m.

Original Summarized

Backdoored Telnyx PyPI package pushes malware hidden in WAV audio

News

Featured
Latest

Popular LiteLLM PyPI package backdoored to steal credentials, auth tokens

HackerOne discloses employee data breach after Navia hack

Firefox now has a free built-in VPN with 50GB monthly data limit

Infinite Campus warns of breach after ShinyHunters claims data theft

Backdoored Telnyx PyPI package pushes malware hidden in WAV audio

Fake VS Code alerts on GitHub spread malware to developers

Agentic GRC: Teams Get the Tech. The Mindset Shift Is What's Missing.

European Commission investigating breach after Amazon cloud account hack

Tutorials

Latest
Popular

How to access the Dark Web using the Tor Browser

How to enable Kernel-mode Hardware-enforced Stack Protection in Windows 11

How to use the Windows Registry Editor

How to backup and restore the Windows Registry

How to start Windows in Safe Mode

How to remove a Trojan, Virus, Worm, or other Malware

How to show hidden files in Windows 7

How to see hidden files in Windows

Webinars
Downloads

Latest
Most Downloaded

Qualys BrowserCheck

STOPDecrypter

AuroraDecrypter

FilesLockerDecrypter

AdwCleaner

ComboFix

RKill

Junkware Removal Tool

Deals

Categories

eLearning

IT Certification Courses

Gear + Gadgets

Security

VPNs

Popular

Best VPNs

How to change IP address

Access the dark web safely

Best VPN for YouTube

Forums
More

Virus Removal Guides
Startup Database
Uninstall Database
Glossary
Send us a Tip!
Welcome Guide

HomeNewsSecurityBackdoored Telnyx PyPI package pushes malware hidden in WAV audio

Backdoored Telnyx PyPI package pushes malware hidden in WAV audio

By Bill Toulas

March 27, 2026
05:13 PM
0

TeamPCP hackers compromised the Telnyx package on the Python Package Index today, uploading malicious versions that deliver credential-stealing malware hidden inside a WAV file.
The supply-chain attack was observed by modern application security Aikido, Socket, and Endor Labs, and was attributed to TeamPCP based on the same exfiltration pattern and RSA key seen in previous incidents caused by the same actor.
TeamPCP is responsible for multiple recent supply-chain (e.g., Aqua Security's Trivy vulnerability scanner, the open-source Python library LiteLLM) and wiper attacks targeting Iranian systems.
Earlier today, the threat actor published backdoored versions of the Telnyx package 4.87.1 and 4.87.2. On Linux and macOS, the malicious version drops malware that steals SSH keys, credentials, cloud tokens, cryptocurrency wallets, environment variables, and other types of secrets.
On Windows, the malware is dropped for persistence in the startup folder, running on every login.
The Telnyx PyPI package is the official Python software development kit (SDK) that allows developers to integrate Telnyx communication services like VoIP, messaging (SMS, MMS, WhatsApp), fax, and IoT connectivity into their applications.
The package is very popular, having over 740,000 downloads per month on PyPI.
Security researchers believe that the hackers breached the project using stolen credentials for the publishing account on the PyPI registry.
Initially, TeamPCP published Telnyx version 4.87.1 at 03:51 UTC, but the package had a malicious yet non-functioning payload. The threat actor corrected the error about an hour later at 04:07 UTC by publishing Telnyx version 4.87.2.
The malicious code is contained in the ‘telnyx/_client.py’ file, which triggers automatically at import, while allowing the legitimate SDK classes to function as expected.
On Linux and macOS systems, the payload spawns a detached process that downloads a second-stage disguised as a WAV audio file (ringtone.wav) from a remote command-and-control (C2) server.

Function handling the steganographic fileSource: Endor Labs
By using steganography, the threat actor embedded malicious code in the file's data frames without altering the audio. The payload is extracted using a simple XOR-based decryption routine and executes in memory to harvest sensitive data from the infected host.
If Kubernetes is running on the machine, the malware enumerates cluster secrets and deploys privileged pods across nodes, attempting to access the underlying host systems.
On Windows systems, the malware downloads a different WAV file (hangup.wav) that extracts an executable named msbuild.exe.
The executable is placed in the Startup folder for persistence across system reboots, while a lock file limits repeated execution within 12-hour windows.
The researchers warn that Telnyx SDK version 4.87.0 is the clean variant that includes the legitimate Telnyx code with no alterations. Developers are strongly advised to roll back to this release if they find Telnyx version 4.87.1 and 4.87.2 in their environments.
Any system that imported the malicious package versions should be treated as fully compromised, as the payload executes at runtime and may have already exfiltrated sensitive data. In such occurrences, it is recommended to rotate all secrets as soon as possible.

Automated Pentesting Covers Only 1 of 6 Surfaces.
Automated pentesting proves the path exists. BAS proves whether your controls stop it. Most teams run one without the other.This whitepaper maps six validation surfaces, shows where coverage ends, and provides practitioners with three diagnostic questions for any tool evaluation.
Get Your Copy Now

Related Articles:
GlassWorm malware hits 400+ code repos on GitHub, npm, VSCode, OpenVSXPopular LiteLLM PyPI package backdoored to steal credentials, auth tokensTeamPCP deploys Iran-targeted wiper in Kubernetes attacksTrivy supply-chain attack spreads to Docker, GitHub reposTrivy vulnerability scanner breach pushed infostealer via GitHub Actions

Backdoor
Information Stealer
PyPI
Supply Chain
Supply Chain Attack
TeamPCP
Telnyx

Bill Toulas
Bill Toulas is a tech writer and infosec news reporter with over a decade of experience working on various online publications, covering open-source, Linux, malware, data breach incidents, and hacks.

Previous Article

Post a Comment Community Rules

You need to login in order to post a comment

Not a member yet? Register Now

You may also like:

Popular Stories

Popular LiteLLM PyPI package backdoored to steal credentials, auth tokens

Kali Linux 2026.1 released with 8 new tools, new BackTrack mode

Firefox now has a free built-in VPN with 50GB monthly data limit

Sponsor Posts

Is your program ready for agentic GRC? See what shift enterprise teams need to make.

Are your AI accounts being sold on the dark web? Check for free. 

Overdue a password health-check? Audit your Active Directory for free

AI is a data-breach time bomb: Read the new report

Synthetic Identities, Proxies & Real Identities for Sale, is yours next?

  Upcoming Webinar

Follow us:

Main Sections

News
Webinars
VPN Buyer Guides
SysAdmin Software Guides
Downloads
Virus Removal Guides
Tutorials
Startup Database
Uninstall Database
Glossary

Community

Forums
Forum Rules
Chat

Useful Resources

Welcome Guide
Sitemap

Company

About BleepingComputer
Contact Us
Send us a Tip!
Advertising
Write for BleepingComputer
Social & Feeds
Changelog

Terms of Use - Privacy Policy - Ethics Statement - Affiliate Disclosure

Copyright @ 2003 - 2026 Bleeping Computer® LLC - All Rights Reserved

Login

Username

Password

Remember Me

Sign in anonymously

Sign in with Twitter

Not a member yet? Register Now


Reporter

Help us understand the problem. What is going on with this comment?

Spam

Abusive or Harmful

Inappropriate content

Strong language

Other

Read our posting guidelinese to learn what content is prohibited.

Submitting...
SUBMIT

The Telnyx PyPI package, a Software Development Kit (SDK) facilitating integration with Telnyx communication services, experienced a significant supply-chain attack orchestrated by the TeamPCP hacking group. This incident highlights the vulnerabilities inherent in relying on third-party packages and the potential for sophisticated attackers to inject malicious code. The attack, observed by Aikido, Socket, and Endor Labs, began with the publication of a compromised version of Telnyx 4.87.1, subsequently corrected with the malicious 4.87.2 release.

The core of the attack involved inserting a backdoor within the ‘telnyx/_client.py’ file, triggering at import, to allow legitimate SDK functionality while simultaneously enabling data exfiltration. Specifically, on Linux and macOS systems, the malware leverages steganography to embed malicious code within a WAV audio file (ringtone.wav), extracted via an XOR-based decryption routine. This allows the threat actor to harvest sensitive information such as SSH keys, credentials, cloud tokens, and cryptocurrency wallet data. On Windows, the malware deploys a different WAV file (hangup.wav) which in turn extracts and executes an msbuild.exe file, establishing persistence through a startup folder and applying a 12-hour execution lockout to reduce the attack’s repeatability. Furthermore, for Kubernetes environments, the malware extends its reach by enumerating cluster secrets and deploying privileged pods across nodes, attempting to access underlying host systems.

The initial publication of Telnyx 4.87.1, containing a non-functional payload, was quickly followed by the actor’s correction of the malicious code, demonstrating a typical pattern in supply-chain attacks. The incident underscores the importance of robust vulnerability scanning and continuous monitoring of package dependencies. TeamPCP has a documented history of targeting Iranian systems with wiper attacks and supply-chain compromises. Security researchers strongly advise developers to revert to the clean Telnyx SDK version 4.87.0 if they have inadvertently incorporated the compromised 4.87.1 or 4.87.2 releases. Given the runtime execution of the payload and potential for data exfiltration, any system utilizing these packages should be immediately treated as fully compromised, necessitating a prompt rotation of all secrets. The attack reinforces the critical need for developers to maintain vigilance across their software supply chains and to implement rigorous security practices when integrating third-party components.