Brevo supply chain attack hits 100k+ sites with Wordpress backdoors and Clickfix malware
released on 2026-09-17 @ 08:54:16 PM
A significant supply chain attack compromised Brevo's infrastructure on September 14, 2026, affecting over 100,000 customer websites. Attackers injected malicious code into Brevo's JavaScript assets and widgets, delivering two distinct payloads: a WordPress plugin backdoor automatically installed when site administrators visited their own sites while logged in, and ClickFix overlays targeting regular visitors. The attack vector involved modification of Brevo's CDN-hosted files and creation of malicious subdomains under sendibt1.com. Evidence suggests attackers gained access to Brevo's Cloudflare account, allowing them to modify DNS records and rewrite content dynamically. The malicious activity lasted approximately four hours, from 16:05 to 20:12 UTC. Brevo's prominent clients include eBay, Louis Vuitton, Michelin, and Amnesty International, amplifying the attack's potential impact significantly.