Malicious code in claude-code-base-action (npm)
The npm package claude-code-base-action v2.0.0 was identified as malicious by both Amazon Inspector and the OpenSSF Package Analysis project. The package communicates with a domain associated with malicious activity.
- Disclosed
- Last updated
- Blast radius
- Unknown; depends on adoption of claude-code-base-action v2.0.0
- Ecosystems
- Attack vectors
- Affected entities
- claude-code-base-action · 2.0.0
The npm package claude-code-base-action v2.0.0 was flagged as malicious by multiple security sources. Amazon Inspector and the OpenSSF Package Analysis project independently identified the package as containing malicious code.
According to the OpenSSF analysis, the package communicates with a domain associated with malicious activity, indicating potential data exfiltration, command-and-control communication, or similar malicious behavior.
The advisory was published on 2026-07-27 via GitHub's advisory system (GHSA-3x98-842h-2764). The package has been identified and reported through established security channels.
Indicators of compromise
- Packages
- claude-code-base-action@2.0.0
Remediation
- Remove claude-code-base-action v2.0.0 from all environments
- Audit systems that installed or executed this package for signs of compromise
- Review network logs for connections to the malicious domain identified in the analysis
- Use alternative, verified packages for the intended functionality
- Monitor npm registry for any related malicious packages
Sources
- GitHub Advisory GHSA-3x98-842h-2764 · GitHub Advisory Database
Cite this entry
"Malicious code in claude-code-base-action (npm)." supplychainattack.org, Supply Chain Attack Incident Catalog. Disclosed July 27, 2026; last updated July 27, 2026. https://supplychainattack.org/incident/malicious-code-in-claude-code-base-action-npm-fbja2k
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