(Credit: Bangla press via Shutterstock)
Microsoft-owned GitHub, a major platform for software developers, has suffered a breach traced to an employee device that was infected with malware.
GitHub disclosed the breach on Tuesday and said it involved a "poisoned" extension for Visual Studio Code, a Microsoft code editor. "We removed the malicious extension version, isolated the endpoint, and began incident response immediately," GitHub tweeted.
The incident raises fears that the hackers gained access to sensitive private software code and customer data on GitHub, which has over 180 million users. However, GitHub stressed that “our current assessment is that the activity involved exfiltration of GitHub-internal repositories only. The attacker’s current claims of ~3,800 repositories are directionally consistent with our investigation so far.”
In response, GitHub has been locking down its systems by rotating “critical secrets” to prevent the hackers from regaining access.
GitHub didn't name the Visual Studio Code extension. But it looks like it was Nx Console, which is hosted on marketplace.visualstudio.com. The extension's developer, Nx, tweeted: "We’re continuing to work with Microsoft and GitHub to investigate the impact of the malicious Nx Console version 18.95.0."
"Initially, Microsoft indicated to us that there were 28 installs of the malicious version 18.95.0. Based on our own analytics for the compromised version, we currently believe the number of users who received the malicious package may be significantly higher; potentially over 6k installs," added Nx CEO Jeff Cross.
Nx's investigation indicates that the malicious version was live on the Visual Studio Marketplace for about 18 minutes on Monday. StepSecurity notes that the extension has over 2.2 million installations. "If you have this version installed, assume your system is compromised," it warned.
The malware works by quietly stealing login credentials for developer accounts at GitHub, npm, AWS, HashiCorp Vault, Kubernetes, and 1Password.
"The payload also specifically targets Claude Code configuration files (~/.claude/settings.json), marking what may be one of the first supply chain payloads designed to harvest AI coding assistant credentials and configurations," StepSecurity adds.
On how Nx was compromised, it said: "One of our developers were compromised by a recent security incident which leaked their Github credentials. These credentials have been temporarily revoked."
GitHub didn’t name the hackers. But a group called TeamPCP has been claiming credit for the breach, alleging it stole GitHub’s source code, which is now up for sale to the highest bidder.
“As always this is not a ransom, we do not care about extorting Github, 1 buyer and we shred the data on our end, it looks like our retirement is soon so if no buyer is found we will leak it free,” the group wrote in a hacker’s forum.
TeamPCP has been hitting numerous companies and organizations by finding ways to circulate malicious versions of popular software development tools. This recently included spreading Trojanized versions of an open-source software library called Tanstack through its official channels, which landed on two employee devices at OpenAI.
Microsoft didn’t immediately respond to a request for comment. But marketplace.visualstudio.com has been caught hosting malicious VS Code extensions before.