Malicious code in animatecss-postcss-plugin (npm)
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (6be12cec08d0999c157774b746c3e431825ae61635bb8ddddf36061d4602cec7) [email protected] ships a tiny PostCSS plugin factory whose body contains an obfuscator.io-style string-array + RC4 decoder (functions _0xa311, _0x4399, _0x12b0 with a ~120-entry encoded string table). When the exported plugin factory is invoked during a CSS build, it constructs a URL from the decoded string array, performs an HTTP fetch with a 60s AbortController and a retry loop (attempts 1..10), base64-decodes the response body's `message` field via Buffer.from(k, 'base64').toString('utf-8'), and executes the resulting JavaScript via `new Function('require', _)(require)` — giving the remote payload full Node `require` access inside the developer's build process. There is no legitimate reason for a PostCSS prefix-injection plugin to fetch and eval remote code, and the heavy obfuscation around the fetch destination and payload-handling logic confirms intent to hide the behavior from casual review. Any project that installs this plugin and runs its CSS build will execute attacker-controlled JavaScript with the privileges of the build process. ## Source: ghsa-malware (d47c1d7e46882283bbc8692e516a9523b7a15dd96654d68799c1c31b9040e65c) 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 animatecss-postcss-plugin versions 1.0.0 to 1.0.1 include a PostCSS plugin factory that uses obfuscated code to fetch a remote payload during the CSS build. The plugin decodes a remote URL, performs an HTTP fetch with retries, base64-decodes the response's 'message' field, and executes it via a new Function call with full Node.js require access. This allows arbitrary attacker-controlled JavaScript execution within the developer's build process, representing a severe supply chain compromise. The obfuscation and remote code execution have no legitimate purpose and indicate intentional malicious behavior.
Potential Impact
Systems that install and run this package execute attacker-controlled JavaScript with the privileges of the build process, potentially leading to full system compromise. Any secrets or keys stored on the affected system may be exposed or stolen. Removing the package does not guarantee removal of all malicious artifacts, as the attacker may have established persistent access.
Mitigation Recommendations
Remove the animatecss-postcss-plugin package versions 1.0.0 through 1.0.1 immediately from all systems. Rotate all secrets and keys that were stored or accessible on affected systems from a separate, trusted environment. Treat any affected system as fully compromised and perform a thorough incident response and forensic analysis. There is no official patch or fix available; remediation requires removal and secret rotation.
Malicious code in animatecss-postcss-plugin (npm)
Description
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (6be12cec08d0999c157774b746c3e431825ae61635bb8ddddf36061d4602cec7) [email protected] ships a tiny PostCSS plugin factory whose body contains an obfuscator.io-style string-array + RC4 decoder (functions _0xa311, _0x4399, _0x12b0 with a ~120-entry encoded string table). When the exported plugin factory is invoked during a CSS build, it constructs a URL from the decoded string array, performs an HTTP fetch with a 60s AbortController and a retry loop (attempts 1..10), base64-decodes the response body's `message` field via Buffer.from(k, 'base64').toString('utf-8'), and executes the resulting JavaScript via `new Function('require', _)(require)` — giving the remote payload full Node `require` access inside the developer's build process. There is no legitimate reason for a PostCSS prefix-injection plugin to fetch and eval remote code, and the heavy obfuscation around the fetch destination and payload-handling logic confirms intent to hide the behavior from casual review. Any project that installs this plugin and runs its CSS build will execute attacker-controlled JavaScript with the privileges of the build process. ## Source: ghsa-malware (d47c1d7e46882283bbc8692e516a9523b7a15dd96654d68799c1c31b9040e65c) 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 animatecss-postcss-plugin versions 1.0.0 to 1.0.1 include a PostCSS plugin factory that uses obfuscated code to fetch a remote payload during the CSS build. The plugin decodes a remote URL, performs an HTTP fetch with retries, base64-decodes the response's 'message' field, and executes it via a new Function call with full Node.js require access. This allows arbitrary attacker-controlled JavaScript execution within the developer's build process, representing a severe supply chain compromise. The obfuscation and remote code execution have no legitimate purpose and indicate intentional malicious behavior.
Potential Impact
Systems that install and run this package execute attacker-controlled JavaScript with the privileges of the build process, potentially leading to full system compromise. Any secrets or keys stored on the affected system may be exposed or stolen. Removing the package does not guarantee removal of all malicious artifacts, as the attacker may have established persistent access.
Mitigation Recommendations
Remove the animatecss-postcss-plugin package versions 1.0.0 through 1.0.1 immediately from all systems. Rotate all secrets and keys that were stored or accessible on affected systems from a separate, trusted environment. Treat any affected system as fully compromised and perform a thorough incident response and forensic analysis. There is no official patch or fix available; remediation requires removal and secret rotation.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- MAL-2026-6495
- Osv Schema Version
- 1.7.4
- Aliases
- []
- Ecosystems
- ["npm"]
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a3ef7cd27e9c79719001f52
Added to database: 06/26/2026, 22:06:05 UTC
Last enriched: 07/11/2026, 12:37:05 UTC
Last updated: 07/31/2026, 15:11:37 UTC
Views: 86
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