OpenSSF/OSV advisory MAL-2026-11149 confirms this npm version as malicious. index.mjs executes a top-level async IIFE on import that fetches https://f004.backblazeb2.com/file/dp8hbvocjd2fpza/helper.zip, unzips it into %LOCALAPPDATA%/Microsoft/Windows/sysache, and writes vite-native-helper.vbs to the current user's Windows Startup folder. The VBS launcher uses WScript.Shell to run the unpacked RenameMe.exe on every user logon, giving the fetched binary persistent execution under the...
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in streak-core-math (npm)
Details
index.mjs executes a top-level async IIFE on import that fetches https://f004.backblazeb2.com/file/dp8hbvocjd2fpza/helper.zip, unzips it into %LOCALAPPDATA%/Microsoft/Windows/sysache, and writes vite-native-helper.vbs to the current user's Windows Startup folder. The VBS launcher uses WScript.Shell to run the unpacked RenameMe.exe on every user logon, giving the fetched binary persistent execution under the installer's account. All sensitive strings (the URL, process/fetch/child_process/fs identifiers, AppData/Startup paths, and the VBS body) are stored as hex literals in a `_c` table and decoded at runtime via `Buffer.from(h,'hex').toString()`, hiding the behavior from static inspection. Execution is gated to skip CI, NODE_ENV=production, and browser contexts, so it fires specifically on developer Windows machines. The filenames (vite-native-helper.vbs, sysache) and comments framing the block as a benign startup self-check are cover-story naming inconsistent with the package's advertised math-helper purpose.
Decision reason
OpenSSF Malicious Packages via OSV confirms streak-core-math@1.0.0 as malicious (MAL-2026-11149): Malicious code in streak-core-math (npm)