A group of Israeli researchers found thousands of potentially harmful extensions on the Visual Studio Code (VSCode) Marketplace, with some having millions of downloads. The researchers created a fake extension mimicking the popular ‘Dracula Official’ theme, dubbed ‘Darcula’, which included risky code to collect system information. This extension was downloaded by multiple high-value targets, including a publicly listed company and major security firms.

Using a custom tool called ‘ExtensionTotal’, the researchers discovered 1,283 extensions with known malicious code, 8,161 communicating with hardcoded IP addresses, and 1,452 running unknown executables. Despite reporting these findings to Microsoft, many of these extensions remained available for download as little as a day ago.

The researchers warn that the lack of stringent security controls on the VSCode Marketplace poses a significant threat to organizations.