GitHub Breach Exposes 3,800 Internal Repositories After Malicious VS Code Extension Attack by TeamPCP
The group alleged it had stolen GitHub source code and thousands of private repositories and is now attempting to sell the data for at least $50,000.
GitHub has confirmed that hackers gained unauthorised access to around 3,800 internal repositories after a compromised Visual Studio Code extension infected an employee's device, triggering a major security incident at the Microsoft-owned developer platform.
The breach was detected on May 18 and has been linked to the cybercriminal group TeamPCP, which later claimed responsibility for the attack on the Breached cybercrime forum.
The group alleged it had stolen GitHub source code and thousands of private repositories and is now attempting to sell the data for at least $50,000.
GitHub said the intrusion originated from a “poisoned” VS Code extension. Visual Studio Code, Microsoft’s widely used open-source coding editor, is deeply integrated into developer workflows and frequently used alongside GitHub Copilot, the company’s AI coding assistant.
After discovering the breach, GitHub said it immediately removed the malicious extension, isolated the affected endpoint and began rotating sensitive credentials.
The company removed the malicious extension version, isolated the endpoint and began incident response immediately.
It also said there was no evidence of impact to customer information stored outside of GitHub’s internal repositories.
"Some of GitHub’s internal repositories contain information from customers, for example, excerpts of support interactions. If any impact is discovered, we will notify customers via established incident response and notification channel," Alexis Wales, GitHub Chief Information Security Officer, said in a blog post.
TeamPCP has rapidly gained notoriety for software supply chain attacks targeting open-source ecosystems, developer tools and cloud infrastructure.
The group has previously compromised packages on the Python Package Index and targeted widely used security tools to steal credentials, cloud keys and Kubernetes configurations.
The hackers warned they may publicly leak the stolen GitHub data if no buyer emerges, raising concerns about potential downstream risks for developers and enterprise customers.
"We continue to analyse logs, validate secret rotation, and monitor our infrastructure for any follow-on activity. We will take additional action as the investigation warrants," Wales added.
