A threat actor called TigerJack is constantly targeting developers with malicious extensions published on Microsoft's Visual Code (VSCode) marketplace and OpenVSX registry to steal cryptocurrency and plant backdoors. Two of the extensions, removed from VSCode after counting 17,000 downloads, are still present on OpenVSX. Furthermore, TigerJack republishes the same malicious code under new names on the VSCode marketplace. OpenVSX is a community-maintained open-source extension marketplace operating as an alternative to Microsoft’s platform, providing an independent, vendor-neutral registry. It is also the default marketplace for popular VSCode-compatible editors that are technically or legally restricted from VSCode, including Cursor and Windsurf. The campaign was spotted by researchers at Koi Security and has distributed at least 11 malicious VSCode extensions since the beginning of the year. The two of those extensions kicked from the VSCode marketplace are named C++ Playground and HTTP Format, and have been reintroduced on the platform through new accounts, the researchers say. When launched, C++ Playground registers a listener (‘onDidChangeTextDocument’) for C++ files to exfiltrate source code to multiple external endpoints. The listener fires about 500 milliseconds after edits to capture keystrokes in near-real time. According to Koi Security, HTTP Format works as advertised but secretly runs a CoinIMP miner in the background, using hardcoded credentials and configuratio...
Malicious crypto-stealing VSCode extensions resurface on OpenVSX
BleepingComputer
·Bill Toulas
·Published Oct 14, 2025
·Updated
Affected Software
4 affected components
Microsoft Visual Code
OpenVSX OpenVSX
Cursor Cursor
Windsurf Windsurf
Frequently Asked Questions
1
What is the main topic of this article?
The article discusses the resurgence of malicious crypto-stealing extensions for Visual Studio Code (VSCode) and OpenVSX.
2
Who is the threat actor mentioned in the article?
The threat actor identified in the article is named TigerJack.
3
What type of malware is being distributed through these extensions?
The extensions aim to steal cryptocurrency and install backdoors on developers' systems.
4
What platforms are affected by these malicious extensions?
The malicious extensions are affecting Microsoft's Visual Code and the OpenVSX registry.
5
What should developers do to protect themselves from these threats?
Developers should verify the authenticity of extensions before installation and monitor for unusual activities.