Typosquatt alert ! Malicious npm Package: nyc-config
On this page
Recently, we discovered a malicious npm package nyc-config in our internal Open Source Software (OSS) package monitoring dashboard. It involved sending user system data to external domains. It is a possible typosquatt attack against the widely adopted @istanbuljs/load-nyc-config, which boasts ~25M weekly downloads.
Discovery and Analysis
Our automated malware analysis flagged the nyc-config package as malicious due to System Information Exfiltration. Upon manual inspection, we observed that the package’s package.json file contained a preinstall script designed to execute the index.js file during installation step itself. This script was crafted to gather sensitive system information such as:
- Hostname
- Operating system details
- Local and public IP addresses
- Username
- Current working directory
The collected data was then exfiltrated to remote servers controlled by the attacker.
You can view the analysis here - https://platform.safedep.io/community/malysis/01JP01T1WQPNGAG516NDS9A6ST
Community Engagement
Recognizing the severity of this threat, we promptly reported our findings to the Open Source Security Foundation (OSSF) - https://github.com/ossf/malicious-packages/pull/839
Conclusion
This incident underscores the critical importance of being cautious when incorporating third-party packages, ensuring they originate from trusted sources. By staying vigilant and fostering collaborative efforts, we can collectively mitigate the risks posed by malicious actors and fortify the security of our development environments.
- npm
- malware
- typosquatting
- open-source security
Author
SafeDep Team
safedep.io
Share
The Latest from SafeDep blogs
Follow for the latest updates and insights on open source security & engineering
DirtyBlanket: Fake Express Packages on npm Spread a Linux Worm
Nine fake Express and React packages on npm run a Linux worm at install time. It installs a Tor backdoor and spreads through SSH, AUR packages, and npm tokens.
Mini Shai-Hulud Is Still Infecting GitHub Repositories
The May 2026 Mini Shai-Hulud worm is still infecting new GitHub repositories. Hijacked actions-cool/issues-helper tags planted Claude Code and VS Code hooks in six popular repositories between 20 and...
Detecting Compromised AI Coding Agents with Jev and Gryph
I checked every action of my own Claude Code agent against a profile of how I work and a set of org policies, using Jev. It caught 14 of 14 attacks for $0.15 per 1,000 events.
MemTensor npm and PyPI Packages Hit by a Go Worm
An attacker used a Go worm to steal CI publish tokens from MemTensor and ship malicious MemOS packages to npm and PyPI. See how it works, with code and indicators of compromise.
Ship Code.
Not Malware.
Start free with open source tools on your machine. Scale to a unified platform for your organization.