folder-lint@1.0.17
Malicious code in folder-lint (npm)
T1195.002 · Compromise Software Supply ChainT1059.007 · JavaScriptT1105 · Ingress Tool TransferT1027 · Obfuscated Files or Information
Analysis
folder-lint@1.0.17 contains a preinstall hook (setup.mjs) that downloads the Bun JavaScript runtime from github[.]com/oven-sh/bun/releases and then executes a 727KB heavily-obfuscated file (math_init.js) through it. The obfuscated payload makes up ~96% of the package and uses a custom base64 decoder with a large lookup table. The package's lib/ directory contains a decoy folder-linting library while the actual malicious behaviour runs at install time via the preinstall script.
- analyzed by
- Leitwacht
- first seen
- Aug 4, 2026, 11:29 AM
- analyzed
- Aug 4, 2026, 11:42 AM
Related advisories
- editable-contracts@0.0.23
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- @servicetitan/carto-charts-react@0.0.6
- @servicetitan/titan-chat-ui-anvil2@9.0.5
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- @servicetitan/carto-charts-rn@0.0.6
- @servicetitan/anvil-react@0.11.7
Independently detected by the Leitwacht supply-chain probe. IOCs are defanged. Published CC0. Think this is a mistake? See the dispute policy.