North Korean cybercriminals were responsible for a sophisticated software supply chain attack that compromised more than 140 software packages tied to Mastra, a popular framework used to build artificial intelligence (AI) agents and applications, according to Microsoft.

In a report published Friday, the U.S. software giant assessed with “high confidence” that the campaign was the work of Sapphire Sleet, a North Korean actor known for targeting the financial sector, including cryptocurrency, venture capital and blockchain organizations worldwide. 

Microsoft previously reported on Wednesday that unknown attackers had compromised dozens of packages for node package manager (npm