Malicious code in postcss-animate-css-vars (npm)
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (5e40aa4b6595789e4ba4b39f82e63526286b36a64ffad2be27536c69c8207590) src/normalize-options.js is heavily obfuscated (RC4-decoded string array, hex-numeric literals, rotating string-array shuffler, dead-code comparison branches) while the rest of the package (index.js, plugin.js, root.js, declarations.js) is plain readable code. When the PostCSS plugin is instantiated (createPlugin -> normalizeOptions), the loader assembles an HTTPS URL from obfuscated string-array entries, appends keys from the caller-supplied options.features sub-object as query parameters, fetches a JSON response, base64-decodes its `message` field, and executes the decoded code with `new Function('require', code)(require)` — arbitrary code execution in every downstream consumer's build/CI process. The loader also writes a wrapper file to the OS tmpdir (named with process.pid) containing `require('<pkg>')(<options>); setInterval(()=>{},2147483647);` and spawns `process.execPath` detached with stdio ignored and env `LT1_STAGE1_CHILD=1`, then calls `child.unref()`. The detached node child re-enters the loader branch, decoupling the fetch-and-eval from the parent build and keeping it alive on a ~24.8-day interval after PostCSS exits, enabling persistent staging beyond the build window. Package metadata (name postcss-animate-css-vars, description 'PostCSS plugin for animate.css', author 'Alex Rivera <[email protected]>', homepage cssanimation.dev) presents as a legitimate PostCSS ecosystem plugin, but the shipped code contains no animate.css handling in the obfuscated loader path — the metadata is cover for the loader. ## Source: ghsa-malware (28c95517227820c9394897cf41111e5a6992063c2ea1b0f0f9fcb1e530189eac) Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
AI Analysis
Technical Summary
The postcss-animate-css-vars npm package version 2.0.3 includes an obfuscated loader that, upon plugin instantiation, constructs an HTTPS URL from obfuscated strings and caller-supplied options, fetches a JSON response, base64-decodes a 'message' field, and executes the decoded code using a new Function call with require access. It also writes a wrapper file to the OS temporary directory and spawns a detached Node.js child process with environment variable LT1_STAGE1_CHILD=1, which re-enters the loader code path and maintains persistence by running on a roughly 24.8-day interval after the parent process exits. The package metadata falsely presents it as a legitimate PostCSS plugin for animate.css, but the obfuscated loader contains no animate.css handling, indicating the metadata is a cover for malicious activity. This behavior enables arbitrary code execution and persistent compromise of any system using this package.
Potential Impact
Any system that installs or runs postcss-animate-css-vars version 2.0.3 is subject to arbitrary code execution during build or CI processes, leading to full system compromise. The malicious code establishes persistence by spawning a detached Node.js process that continues running beyond the build lifecycle. This can result in unauthorized access, data exfiltration, and control over the affected system. All secrets and keys stored on the compromised system should be considered exposed and require immediate rotation from a secure environment.
Mitigation Recommendations
No official patch or fix is currently documented for this malicious package version. Immediate removal of postcss-animate-css-vars version 2.0.3 from all systems is strongly recommended. Due to the persistence mechanism, assume full system compromise and perform comprehensive incident response, including rotating all secrets and credentials from unaffected systems. Monitor for any spawned detached Node.js processes and remove any related files from the OS temporary directory. Verify build and CI environments for signs of compromise and rebuild from trusted sources.
Malicious code in postcss-animate-css-vars (npm)
Description
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (5e40aa4b6595789e4ba4b39f82e63526286b36a64ffad2be27536c69c8207590) src/normalize-options.js is heavily obfuscated (RC4-decoded string array, hex-numeric literals, rotating string-array shuffler, dead-code comparison branches) while the rest of the package (index.js, plugin.js, root.js, declarations.js) is plain readable code. When the PostCSS plugin is instantiated (createPlugin -> normalizeOptions), the loader assembles an HTTPS URL from obfuscated string-array entries, appends keys from the caller-supplied options.features sub-object as query parameters, fetches a JSON response, base64-decodes its `message` field, and executes the decoded code with `new Function('require', code)(require)` — arbitrary code execution in every downstream consumer's build/CI process. The loader also writes a wrapper file to the OS tmpdir (named with process.pid) containing `require('<pkg>')(<options>); setInterval(()=>{},2147483647);` and spawns `process.execPath` detached with stdio ignored and env `LT1_STAGE1_CHILD=1`, then calls `child.unref()`. The detached node child re-enters the loader branch, decoupling the fetch-and-eval from the parent build and keeping it alive on a ~24.8-day interval after PostCSS exits, enabling persistent staging beyond the build window. Package metadata (name postcss-animate-css-vars, description 'PostCSS plugin for animate.css', author 'Alex Rivera <[email protected]>', homepage cssanimation.dev) presents as a legitimate PostCSS ecosystem plugin, but the shipped code contains no animate.css handling in the obfuscated loader path — the metadata is cover for the loader. ## Source: ghsa-malware (28c95517227820c9394897cf41111e5a6992063c2ea1b0f0f9fcb1e530189eac) Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The postcss-animate-css-vars npm package version 2.0.3 includes an obfuscated loader that, upon plugin instantiation, constructs an HTTPS URL from obfuscated strings and caller-supplied options, fetches a JSON response, base64-decodes a 'message' field, and executes the decoded code using a new Function call with require access. It also writes a wrapper file to the OS temporary directory and spawns a detached Node.js child process with environment variable LT1_STAGE1_CHILD=1, which re-enters the loader code path and maintains persistence by running on a roughly 24.8-day interval after the parent process exits. The package metadata falsely presents it as a legitimate PostCSS plugin for animate.css, but the obfuscated loader contains no animate.css handling, indicating the metadata is a cover for malicious activity. This behavior enables arbitrary code execution and persistent compromise of any system using this package.
Potential Impact
Any system that installs or runs postcss-animate-css-vars version 2.0.3 is subject to arbitrary code execution during build or CI processes, leading to full system compromise. The malicious code establishes persistence by spawning a detached Node.js process that continues running beyond the build lifecycle. This can result in unauthorized access, data exfiltration, and control over the affected system. All secrets and keys stored on the compromised system should be considered exposed and require immediate rotation from a secure environment.
Mitigation Recommendations
No official patch or fix is currently documented for this malicious package version. Immediate removal of postcss-animate-css-vars version 2.0.3 from all systems is strongly recommended. Due to the persistence mechanism, assume full system compromise and perform comprehensive incident response, including rotating all secrets and credentials from unaffected systems. Monitor for any spawned detached Node.js processes and remove any related files from the OS temporary directory. Verify build and CI environments for signs of compromise and rebuild from trusted sources.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- MAL-2026-12418
- Osv Schema Version
- 1.7.4
- Ecosystems
- ["npm"]
Threat ID: 6a73574fbf8831d53915a5c3
Added to database: 08/05/2026, 15:31:27 UTC
Last enriched: 08/21/2026, 16:59:19 UTC
Last updated: 09/16/2026, 12:14:43 UTC
Views: 28
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