diff --git a/README.md b/README.md
index 7b2d7f7d..cf14ff8a 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,9 @@
 ![Perl](https://img.shields.io/badge/-Perl-39457E?logo=perl&logoColor=white)
 ![Markdown](https://img.shields.io/badge/-Markdown-000000?logo=markdown&logoColor=white)
 
+> [!WARNING]
+> **Official sources only.** Install ECC only from verified channels: the GitHub repository [github.com/affaan-m/ECC](https://github.com/affaan-m/ECC), the npm packages [`ecc-universal`](https://www.npmjs.com/package/ecc-universal) and [`ecc-agentshield`](https://www.npmjs.com/package/ecc-agentshield), the [GitHub App](https://github.com/apps/ecc-tools), the plugin slug `ecc@ecc`, and the project website [ecc.tools](https://ecc.tools). Third-party re-uploads and unofficial mirrors are not maintained or reviewed by the project and may contain malware.
+
 > **211.9K+ stars** | **32.5K+ forks** | **230+ contributors** | **12+ language ecosystems** | **Cross-harness agent workflows**
 
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