A Look at the Top Blocked Websites

The report examines Google Safe Browsing data for the Alexa top 1 million sites and finds 621 domains blocked, most because legitimate sites were hijacked to serve obfuscated malicious JavaScript, malicious IFRAMES, fake-AV pages, adware downloads and exploit payloads (including a Flash heap spray targeting macOS and IE exploits for Windows). It highlights examples of popular compromised sites, geographic hosting trends (US and Western Europe prominent), and emphasizes that Google often denylists the infected site rather than only the external malicious hosts.