What our analysis found

Stacker - Falling tetra blocks!, used by 600,000 people, is rated caution by Extension Auditor. Our code review reported 2 findings (2 high), led by unauthorized data collection. It comes from a trusted publisher and was last updated in August 2026.

Key findings

• high· unauthorized data collection —The extension sends page view, client ID, user ID, session ID, and other analytics data to Google Analytics (measurement ID G-PVD4NTS8KT) via a POST request. This data collection is not disclosed in the Chrome Web Store listing (disclosure says 'none declared'), making it unauthorized tracking.
• high· other —On extension install and update, the background script fetches external promotional URLs from 'tetrys-install-urls' and 'tetrys-update-urls' endpoints and automatically opens new tabs with those URLs (active tab on install, background tab on update). This behavior is not clearly disclosed and forcefully injects advertising content, violating user expectations.

The extension sends analytics data (page views, client ID, user ID, etc.) to Google Analytics without any disclosed data collection in the Chrome Web Store listing. Additionally, on install and update, it automatically opens new tabs to external promotional URLs, which is intrusive and not clearly disclosed. While the core game functionality is benign, these behaviors indicate potential adware and undisclosed tracking, making the extension suspicious.