SquareX (now part of Zscaler)

SquareX built a Browser Detection and Response (BDR) platform, applying the detect-and-respond model long used for endpoints and networks to the browser itself, a threat surface that traditional endpoint and network security tools often have limited visibility into. Its capabilities included detection of malicious browser extensions, identity-based attacks conducted through the browser, browser-delivered malware, and browser-native data loss prevention with file isolation, extending consistent protection across managed and unmanaged devices alike.

Backed by Sequoia Capital Southeast Asia and based in Singapore, SquareX built its BDR approach around the idea that the browser has become the primary application most knowledge workers use all day, yet is frequently the least monitored layer of the security stack. On February 5, 2026, Zscaler announced its acquisition of SquareX, stating the deal would extend Zscaler’s Zero Trust Exchange platform’s uncompromising security posture to unmanaged devices via advanced browser-based protections suited to the AI era.

The acquisition reflects the same industry consolidation trend seen with CrowdStrike’s acquisition of Seraphic around the same period, as major security platform vendors race to close browser-layer visibility gaps by acquiring specialized browser security startups rather than building the capability from scratch; SquareX’s technology now operates as part of Zscaler’s platform rather than as a standalone product.