Microsoft’s open source tools hacked to steal AI devs’ passwords

Microsoft has temporarily disabled access to dozens of its open source repositories on GitHub after discovering that hackers injected password-stealing malware into the code. The affected projects are primarily linked to Azure cloud services and tools used by developers working with AI platforms like Claude Code, Gemini’s command line interface, and VS Code.

Security researchers at Cloudsmith and the community-driven malware analysis site OpenSourceMalware were among the first to detect the breach. According to their findings, the malware was designed to steal user passwords and other sensitive credentials when developers opened the compromised tools within their AI coding applications. It remains unclear how many users may have downloaded the infected software.

Microsoft confirmed that it removed the repositories following the discovery, a move first reported by 404 Media. Microsoft spokesperson Ben Hope told TechCrunch that the company “temporarily removed some repositories as we investigated potential malicious content.” He added that some repos have been restored after review, while others remain offline as the investigation continues.

Hope also noted that Microsoft has notified “a small number of customers who may have pulled down content from the affected repositories.” He emphasized that the company will continue investigating and will reach out directly through established support channels if further action is needed. Microsoft did not specify the exact number of affected customers when asked by TechCrunch.

At least 70 Microsoft projects have been disabled, according to a message displayed when attempting to access the repositories on GitHub, which Microsoft owns. The message states: “Access to this repository has been disabled by GitHub Staff due to a violation of GitHub’s terms of service.”

This incident marks the latest in a series of supply chain attacks targeting widely used open source projects. Hackers aim to infect a broad user base by compromising code that is integrated into many software products or used by specific high-value groups, such as developers who often have access to cloud systems and large datasets.

While it is common for individual open source developers to be targeted, it is rare for a major technology company like Microsoft , which has substantial resources to defend against such attacks , to be breached. This is Microsoft’s second known security lapse involving its open source projects in recent weeks. In mid-May, researchers reported that Microsoft’s Durable Task project, a tool for building applications, had been compromised. According to OpenSourceMalware, the current breach represents a “re-compromise” of the Durable Task project, suggesting that Microsoft may not have fully removed the hackers after the first incident, or that a separate new attack has occurred.